Annual Report 1977 Volume 1

AB-101

ECOLOGICAL NON ITORI NG

AT THE FLORIDA POWER R LIGHT CO.

ST, LUCIE PLANT

ANNUAL REPORT 1977

VOLUME 1

Prepared for

. FLORIDA POWER 6 LIGHT COMPANY MIAMI, FLORIDA

Docf!Gt N W~g &~4tlgy i-"."7tlo z.ofO P"'M=SCL7g of Dec>!ment: By i> ~4L'i1~~>Y 06tlKH FiLE APPLIED BIOLOGY, INC.

ATLANTA, GEORGIA

March 1978

TABLE OF CONTENTS

VOLUME 1

~Pa e

A. INTRODUCTION A-1 Background A-1 Area Description A-3 Sampling Design A-5 Figures A-7 Tables A-9

B. FISH AND SHELLFISH 8-1 Introduction 8-1 The Ichthyofaunal Assemblage 8-2 Fish Habitats 8-5 Trophic Interrelationships: The Food Chain 8-7 Impingement 8-10 Materials and Methods 8-10 Results and Discussion 8-12 Inshore (canal) Gill Nets 8-22 Materials and Methods 8-22 Results and Discussion 8-23 Offshore Gill Net 8-26 Materials and Methods 8-26 Results and Discussion 8-27 Trawl 8-32 Materials and Methods 8-32 Results and Discussion 8-33 Beach Seine 8-35 Materials and Methods 8-35 Results and Discussion 8-35 Ichthyoplankton- 8-39 Materials and Methods 8-4O Statistical Analysis 8-42 Results and Discussion 8-43 Summary 8-60 Literature Cited 8-63 Figures 8-69 Tables 8-82

C. MACROINVERTEBRATES C-1 Introducti on C-1 Materials and Methods C-2 Shipek Grab Samples C-2 Trawl Studies C-4 I

I I- ~Pa e C. MACROINVERTEBRATES (continued) Resul ts and Discussion C-5 Substrata C-5 Evaluation of Sample Adequacy for Species Accumulation C-9 Evaluation of Sample Adequacy for Diversity Indices- C-12 Seasonal Variation of Fauna in Benthic Grab Samples- C-13 Critical Variables: Temperature and Substrate ---— C-15 Plant Effects on Benthic Fauna Collected by Grabs: 1976 -1977 C-18 Comparison of Benthic Grab Diversity by Year------C-20 Dominant Benthic Grab Phyla and Taxa C-20 Analysis of Trophic Types C-25 Interstation Comparisons C-26 Comparisons With Baseline Benthic Studies --—----— C-29 Benthic Trawl Data C-29 Summary C-38 Literature Cited C-41 Figures C-45 Tables C-77

D. PHYTOPLANKTON D-1 Introduction D-1 Materials and Methods D-5 Phytoplankton Analysis D-5 Pigment Analysis D-8 Results and Discusssion D-9 Phytoplankton Density D-10 Phytoplankton Community Composition D-l 1 Statistical Evaluation of Offshore Phytoplankton Data D-14 Entrainment and Temperature Relationships ———---— D-15 Pigment Analysis and Primary Productivity --—-—--- D-17 Summary D-23 Literature Cited D-26 Figures- D-30 Tables D-55

E. ZOOPLANKTON E-1 Introduction E-1 Materials and Methods E-2 Results and Discussion E-4 Canal Stations E-6 Offshore Stations E-8 Summary E-12 Literature Ci ted E-14 Figures E-15 Tables E-31 I

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I ~Pa e

F. AQUATIC MACROPHYTES Introduction F-1 Materials and Methods F-2 Results and Discussion F-2 Literature Cited F-5 Figure F-6 Tables F-7

G. WATER QUALITY Introduction G-1 Physical Parameters- G-1 Materials and Methods G-1 Results and Discussion G-5 Chemical Parameters G-8 Materials and Methods G-8 Results and Discussion G-9 Summary G-ll Literature Ci ted G-13 Figures G-14 Tables G-22

H. NESTING TURTLES H-1 Introduction H-1 Mari ne Turtles at Hutchinson Island H-2 Materials and Methods H-3 Results and Discussion H-4 Nesting Activity on Hutchinson Island H-4 Nesting Success at Hutchinson Island,- H-7 Site Specificity H-8 Renesting Intervals H-8 Water Temperatures and Onset of Nesting Season H-9 Predation H-12 Population Size Estimates H-13 Literature Cited H-15 Figures H-17 Tables H-22

I. HATCHLING TURTLE EXPERIMENTS I-l Introduction I-1 Materials and Methods I-4 Hatching and Maintenance I-4 Test Tanks I-5 Light Regimes I-6 Experimental Procedures- I-6 Thermal'Regimes I-7 Lethal Effects I-7

iv I

l ~Pa e I. HATCHLING TURTLE EXPERINENTS (continued) Results- I-8 Swimming Speed at Constant Temperatures ---——----- I-9 Swimming Speed in Fluctuating Temperatures ------I-10 Discussion I-12 Summary I-14 Literature Cited I-16 Figures I-18 Tables I-25 A. INTRODUCTION

BACKGROUND

This document has been prepared in response to the Nuclear Regulatory Commission's Environmental Technical Specifications found

in Appendix B to Operating License No. DPR-67 for Unit No. 1 of

Florida Power 5 Light Company's St. Lucie Plant.

In 1970, Florida Power 8 Light Company (FPL) was issued a con-

struction Permit No. CPPR-74 by the United States Atomic Energy Comnission (now Nuclear Regulatory'Commission). This permit allowed

construction of Unit No. 1 of the St. Lucie Plant, an 850-megawatt

nuclear-powered electric generating station on Hutchinson Island in

St. Lucie County, Florida. Unit 1, was placed on-line in March 1976.

Plant operation was intermittent in 1976 but was base loaded through-

out 1977, except for repair outages.

The St. Lucie Plant presently generates electricity with one

850-megawatt net electric pressurized water reactor. The condenser

cooling water is provided by a once-through circulating water system which consists of intake and discharge pipes in the ocean linked by canals to the plant. Cooling water is drawn from the Atlantic

Ocean through a vertical intake structure located 365 m (1200 ft) offshore. The intake structure is covered with a concrete velocity cap, the top of which is approximately 2.4 m (8 ft) below the water

A-1 I surface. „From the intake point, water is drawn into the intake canal through a pipe buried under the dunes. The 90-m (300-ft) wide canal car ries the cooling water about 1500 m (5000 ft) to the plant intake structure where pumps provide 33,400 liters/sec (530,000 gal/min) of flow. The water moves through the intake screens, passes through the plant condenser s, and is released into the discharge canal.

The design temperature rise of the water passing through the condensers is approximately 24'F (13.4'C). After leaving the plant, the heated water passes thr ough a 69-m (200-ft) wide discharge canal before entering a pipe buried under a 'dune and the ocean floor. The water is carried about 365 m (1200 ft) offshore and discharged through a Y-shaped pipe 5 m (18 ft) below the water surface. The discharge pipe is located 730 m (2400 ft) north of the intake.

The Florida Oepar tment of Natural Resources Marine Research

Laboratory in conjunction with FPL conducted preoperational baseline environmental studies of the marine envi ronment adjacent to the

St. Lucie Plant from September 1971 to July 1974. Applied Biology,

Inc., was contracted by FPL in 1975 to conduct the operational phase of the ecological monitoring program at the St. Lucie Plant. A sampling program was designed in accordance with the Nuclear Regulatory Commission's Environmental Technical Specifications for St. Lucie

Unit No. 1. Preliminary studies on fish populations in the plant's

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l cooling water canals began in December 1975; the complete sampling program was initiated in March 1976. Results of the 1976 study were submitted to FPL by Applied Biology, Inc., in the 1976 Annual Report entitled Ecological Monitoring at the Florida Power 8 Light Co. St.

Lucie Slant. Data generated during the preSent Study Will be COm- pared with results of the baseline study and the 1976 operational study to assess the effects of plant construction and operation on the major biotic communities in the nearshore marine environment.

AREA DESCRIPTION

The St. Lucie Plant is located on a 457.3-hectare (1130-acre) site on Hutchinson Island approximately midway between Ft. Pierce and St. Lucie Inlets on Florida's:lower east coast (Figures A-1 and

A-2). It is bounded on the east by the Atlantic Ocean and on the west by the Indian Rive'r, a shallow lagoonal estuary.

The Indian River is an integral part of the ecosystem in this area, being linked by tidal flushing to the Atlantic Ocean via Ft.

Pierce and St. Lucie Inlets,, and to Lake Okeechobee via the St.

Lucie River and Canal.

Hutchinson Island extends 37.5 km between inlets and obtains a maximum width of 1.8 km at the plant site. Elevations approach 5 m atop dunes bordering the beach, they decrease to sea level in the mangrove swamps that are common on much of the western side. Island

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I vegetation is typical of southeast Florida coastal areas with dense stands of Australian pine, palmetto, sea grape, and spanish bayonet inhabiting the higher elevations, and mangroves in the lower eleva-

tions and swamps. Large portions of the interior mangrove communities

have been extensively altered over past decades by county mosquito control practices. Large stands of black mangroves, including some

on the plant site, have been killed by controlled flooding.

'oquinoid rock formations parallel much of the island off the

ocean beaches and provide suitable substrata for intertidal accumula-

tions of "worm reef." Worm reefs, which resemble stone, are formed

of sand and mucus by colonial marine worms, A relatively extensive

worm reef community lies approximately 0.5 km south of the intake

Relic worm reef formations protrude through present-day pipeline. I beaches along much of the island's southern end.

The ocean bottom offshore from the plant site consists entirely

of sand and shell sediments with no reef obstructions or rock outcroppings. The unstable substrate limits the establishment of rooted macrophytes or attached benthic communities.

The Florida Current, which flows parallel to the continental coastline at West Palm Beach. , shelf margin, begins to diverge from the At Hutchinson Island, the current is approximately 33 km offshore. Oceanic water associated with the western boundary of the current,

A-4 however, especially during summer months, periodically meanders over the inner shelf.

SAMPLING DESIGN

Systematic sampling was continued in 1977 according to the outline in Table A-1. To increase the efficiency of the study, some changes were made in the sampling design. These changes will be discussed in the appropriate sections of this report.

Selection of station locations was based on proposed configur- ations of the thermal plume provided by FPL and the locations of dominant macrohabitats established by the preoperational survey. I Stations used in each phase of the study are shown on maps in the respective sections of the. report.

A description of the offshore stations is given in Table A-2.

Stations 1, 2 and 3 were selected to be perpendicular to the beach on a transect coincident with the postulated slack current thermal plume configuration. Additional offshore stations (4 and 5) were established to the south and north, respectively, of Station 2.

A control station (Station 0) was established south of the plant discharge. g I ~

g I l

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I Three beach seine stations were located near shore, at points north of the discharge (Station 6), south of the intake (Station 8), and midway between those two points (Station 7). Six additional stations were established in the plant intake (Stations 11, 13, 14, and 15) and discharge (Stations 12 and 16) canals.

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TABLE A-1

BIOLOGICAL SAMPLING SCHEDULE (NUMBER SAMPLES/STATION) ST. LUCIE PLANT 1976-1977

Offshore Intake Discha e Section

Adult fish-beach seine 3 3 3- monthly

Adult fish-gill net 1 1 1 1 1 1 1S 1S 1S 1S monthly 18 18 18 18 monthly

Adult fish-otter trawl 1 1 1 1 1 1 monthly Aquatic macrophytes 2 2 2 2 2 2 quarterly

Benthos-trawl 1 1 1 1 1 1 monthly (with adult fish) Benthos-grab 4 4 4 4 4 4 quarterly Ichthyoplankton (fish eggs 5 larvae) 2 2 2 2 2 twice monthly Impingement 2'S twice weekly (with pumps on) Phytoplankton and chlorophyll 2S 2S 2S 2S 2S 2S monthly 28 28 28 28 28 28 28 monthly Thenaograph monitoring Cont. Cont.. monthly Water quality & nutrients 2S 2S 2S 2S 2S 2S 2S monthly 2M 2H 2H 2H 2H 2H monthly 28 28 28 28 28 28 28 monthly Zooplankton 2S 2S 2S 2S 2S 2S monthly 28 28 28 28 28 28 26 monthly ' S = surface sample = mid-depth sample 8 = bottom sample 0 = oblique tow Note: Stations 9 and .10 are part of another study. I

4 TABLE A-2

OESCRIPTION OF OFFSHORE STATIONS ST. LUCIE PLANT 1977

Latitude- Mean sampling Station Lon itude Geo ra hic location de th m Substrate

0 27'19.1'N 4.7 km S of plant discharge, on 8.2 Fine gray sand (control) 80'13.2'W beach terrace

1 27'21.1' 0.5 km offshore, at seaward margin 7.6 Gray, hard-packed 80'14. 1' of beach terrace fine sand

2 '7'21.4'N 1.5 km E-NE of Station 1 in offshore 11.3 Shell hash 80'13.3'W trough, approximately midway between beach terrace and offshore shoal

27'21. 7' 3 km from Station 1, on coincident 7.6 Medium sand with few 80'12. 4' compass heading, atop Pierce Shoal large shell particles

27'20.6'N 1.6 km S-SE of Station 2 and 0.6 km 11.3 Shell hash 80'12.8'W wes t of southernmos t tip of Pi erce Shoal, in offshore trough

27'22.9'N, 2.2 km N-NE of -Station 2 and 2.1 km 11.3 Shell hash 80'14.0'W E of beach, in offshore trough I B ~ FISH AND SHELLFISH

INTRODUCTION

Fishes distribute themselves within the aquatic ecosystem according to their physiological limitations and biological needs.

A consequence of this distribution has been the development of communities or assemblages of fishes which are dependent on the physical conditions and resources of an area. The aquatic communities off Hutchinson Island are unique in that they are transitional between temperate faunas to the north and tropical faunas to the south.

Natural variations in the physical conditions, such as seasonal temperature changes or fluctuations in the proximity of the Florida Current to the coast, could result in variations in the composition or abundance of fishes in the area. Similarly, although on a much more localized scale, effects on fish assemblages could also result from operations of the St. Lucie Plant.

This study, a continuation of the study initiated by Applied

Biology, Inc., in December 1975, was to further document the composition and abundance of fishes in the vicinity of the St. Lucie Plant and to evaluate habitat, distribution and life history aspects of

these fishes. Data obtained were to be used in conjunction with data from the 1976 (ABI, 1977) and baseline (Futch and Dwinell, 1977) studies to determine if plant operations had any significant effect on the fishes in the area.

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I The evaluation of the ichthyofaunal assemblage and the potential effects of plant operation required studies of both inshore and oceanic areas. Inshore samples were taken in the immediate vicinity of the plant. This sampling included collecting impinged specimens at the intake traveling screens and gill netting in the intake and discharge canals. Oceanic samples were taken by gill netting, trawling and beach seini ng. In analyzing oceanic samples, emphasis was placed on

the possible effects of the offshore thermal discharge upon migratory

fishes of sport and commercial importance. Ichthyoplankton sampling was conducted both inshore and offshore to evaluate entrainment and thermal discharge effects, respectively.

Prior to a discussi on of the specific sampling techniques employed, and the results obtained, a brief overview of the ichthyofaunal assemblage is given. This overview is followed by a generalized account of fish habitats and trophic interrelation-

ships ( the food chain) in the vicinity offshore from Hutchinson Island.

The Ichth ofaunal Assembla e

The most comprehensive list of fishes of the Indian River and a adjacent waters has recently been compiled by Gilmore (1977), based

Other, less comprehensive studies included those of Evermann and Bean (1897), V.G. Springer (1960), S. Springer (1963), Gunter and Hall (1963), Christensen (1965), Anderson and Gehringer (1965) and Bullis and Thompson (1965). Briggs (1958) included this area in his distributional study of Florida fishes, although he did not collect there. I f

I on extensive collections and literature review by the Harbor Branch Foundation (see also Gilmore, 1974; Jones et al., 1975). Regarding this ichthyofauna, which includes that of the Hutchinson Island area,

Gilmore (1977) stated that:

The richness of this fauna appears to be directly affected by water temperature modera- tion and recruitment via the Florida Current, moderate inshore salinities, and the transitional zoogeographic setting of the study area. The Indian River region encompasses sever'al biotopes, all of which affect the distribution and composition of the local fish fauna. The study area is broad (latitude 27'00-29'00'N) and includes nearly all of the aquatic fish communities in east Florida... The fish distribution is further complicated by its transitional nature, as the warm-temperature Carolinian and the tropi cal Caribbean fish faunas overl ap considerably here; 285 of the fish fauna is considered tropical, 22% are warm-temperate, and 50/ are eurythermic tropicals and continental species having a wide distribution both north and south of this region.

These Ltropical] fishes originated i n the Cari bbean faunal province and apparently came into the region via the Florida Current. Warm- temperate Carolinian fishes are more commonly found in the open bottom continental shelf bio- tope ... Distribution of the Carolinian species must be explained by adult migration, with some aid from larval fishes transported via south- bound counter-currents of the Florida Current and other inshore water mass movements.

The ilarbor Branch Foundation studies established that at least

654 species of fishes occur in the Indian River lagoon, its tributaries, and the adjacent continental shelf at depths less, than 200 m,

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l l and that at least 704 species should eventually be collected or identified from this area (Gilmore, 1977; Gilmore, personal communication). This research indicated that probably less than 40Ã of the fish species from the Indian River and adjacent areas were characteristic of the surf zone, open bottom and neritic zone (G. Gilmore, personal communication), the three relatively distinct oceanic habitats within the influence of normal operations of the

St. Lucie Plant. The majority of the species were from the rich grass flats within the Indian River lagoon, from around inlets and inshore reefs which provide cover, and from the offshore reefs.

These habitats were either of limited extent (e.g., worm reefs) or

beyond the influence of normal operations of the St. Lucie Plant.

The ichthyofauna offshore from the St. Lucie Plant has been

studied by Applied Biology, Inc., since December 1975 and by the

Florida Department of Natural Resources between September 1971 and

August 1974.

Applied Biology, Inc., personnel have collected or observed

almost 240 species of fishes in the vicinity of the plant (Appendix

Table J-1A). A total of 75 fish species were found during the base-

line study conducted by the Florida Department of Natural Resources

(Futch and Dwinell, 1977). These fishes were collected by trawl

(42 hr effort) and beach seine (9 hr) and were, for the most part,

8-4 I the more common species in the area. Only six species found during the baseline study have not been collected by Applied Biology. All species which are common in the area have probably been found. Future additions to the species list will include the rarer forms such as transients through the area, strays from deeper waters off-

shore, and tropical forms carried inshore with eddies from the Florida Current.

Fish Habitats Three relatively distinct oceanic habitats were within the influence of normal operations of the St. Lucie Plant: surf zone,

open bottom and neritic. zone.

The surf zone was characterized by water turbulence and shifting

sand substrate. Besides the turbulence, a major limiting factor on

fish diversity in this habitat was the lack of cover over the bottom.

Only one small worm-reef protrusion occurred in the vicinity of the

plant, and the amount of cover it provided for fish in the surf zone

was minimal. Little or no attached macroscopic vegetation grew in the surf zone, with the exception of that found on the worm reef. Fishes capable of thriving in this turbulent zone were limited to a

few taxa. Characteristically, these were the bottom feeding carnivores:

Clearnose skate (Raja eglanteria), northern kingfish (zenticirrhus saxatilis), star drum (stellifer lanceolatus), Atlantic threadfin (Polgdactglus octonemus), freckled driftfish (Psenes cyanophyrys) and spotted driftfish (ariomma regulus).

8-5 Il 5 drum (sand drum and kingfish), threadfin and pompano that feed on the burrowing invertebrates such as sand fleas and coquina, which occurred in this habitat. Other fishes, such as the planktivorous herrings and anchovies and the piscivorous jacks, Spanish mackerel and bluefish, are occasionally caught in the surf zone, but are primarily transients. Certain of these transients, particularly herring and anchovy, often occurred in large numbers.

The open bottom beyond the surf zone consisted of a relatively homogeneous shell hash and, like the surf zone, lacked vegetation or other cover that could provide shelter for fishes. Dominant fishes on the open bottom were the flatfishes (flounder, sole and tonguefish), cusk-eels and searobins. These forms have adapted to living in or on the ocean bottom. Protective coloration and the burying behavior of the flatfish, the hard and spiny exterior of the searobin, and the burrowing nature of the cusk-eel provide some protection against predation on these generally small bottom-dwellers. Other common species occurring on or just over the bottom were sand-perch, grunt, mojarra and lizardfish. Additionally, certain taxa were seasonal in occurrence, as evidenced by the large number of juvenile drum collected

(by bottom trawl) in November.

The neritic zone consists of the coastal area of open water beyond the surf zone and above the bottom. The vast majori ty of the

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I fishes found during this study in the vicinity of the St. Lucie Plant were either residents of, or transients through, the neritic zone. Characteristic of the neritic zone were the herrings and anchovies, sharks, mackerels, bluefish and jacks. Nany of the fishes found in this zone were of sport or commercial importance, such as the mackerels, bluefish and tuna, which make large north-south seasonal migrations. Other taxa, such as mullet, menhaden and certain drum, make seasonal migrations from the Indian River lagoon out into neritic waters to spawn. In addition, the Florida Current provides a continuous source of recruitment of tropical forms from south Florida and the Caribbean into the Hutchinson Island area.

Tro hic Interrelationshi s: The Food Chain

The lack of macroscopic vegetation in the open oceanic area offshore from the St. Lucie Plant, in sharp contrast with the extensive grass flats in the adjacent Indian River lagoon, results in a food chain based almost entirely on microscopic algae (phytoplankton).

The phytoplankton use solar energy and dissolved nutrients, and, through photosynthesis, become available to animals as food.

The primary consumers of the phytoplankton are the zooplank-

ton. These animals are also microscopic or semi-microscopic in size

and vast in numbers. Some larval fishes also feed to some extent

on microalgae (Lebour, 1924) and a few, such as menhaden with their

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1 exceptionally fine filtering apparatus, feed partly on diatoms and dinof1agel1 ates throughout life (Bigel ow, 192S) .

It is extremely difficult to obtain measurements of the relative volumes of plants and animals in the sea, although it is obvious

that the mass of plant material produced each day must be considerable to support the grazers. In turn, the grazers of the neritic zone accomplish two important ends: first, the utilization of the primary food and, second, the transformation of this primary food into animal substance of size sufficiently large to be caught and utilized by carnivorous forms (Sverdrup et al., 1942). The large number of carnivores in the neritic zone is evidence of the abundance of the grazers.

The plankton feeders ei ther pick the individual zooplankters

from the water or are equipped with some type of screening device (e.g., gill rakers in certain fishes) through which the water is passed while the small organisms are retained as food. Depending

on the fineness of the screening device, phytoplankton and detritus

may also be retained and i ngested. Differences between these two

methods of feeding are based primarily on the relative degree of

selectivity involved. Many of the copepods (wi thin the zooplankton),

barnacles, mussels, clams and sponges indiscriminately filter plank-

ton from the water. On the other hand, certain copepods, the arrow

worm and ctenophores are active predators which seize zooplankters

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.1 (and larval fishes) that drift within their reach. Among the plankton feeding fishes are the herrings and anchovies, which either select out individual zooplankters or filter indiscriminately with the aid of the gill rakers.

The plankton feeding fishes, such as the herrings and anchovies, generally occur in great abundance and provide the link between the zooplankton and the larger predators. These larger predators are the fishes most familiar to man, such as the sharks, mackerels, bluefish, jacks and billfish.

Another group of organisms within the oceanic food chain, and equally vital to the entire system, consists of the detritus feeders, browsers and scavengers. Although these forms may be separately defined, they all feed more or less indiscriminately upon living or dead organic matter and are combined for purposes of this report.

The majority of the benthic invertebrates are found in this assemblage: polychaetes, echinoderms, gastropods and several crustaceans including crabs, shrimps, amphipods and isopods. Hany of the fishes, in turn, are consi dered "bottom-feeders" and prey on these benthic forms (and each other) both in the surf and over the open bottom.

The more common fishes in this category are the flatfishes, searobins, cusk-eels, lizardfish, pompanos and drums.

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I S As implied .in the preceding discussion, the aquatic flora and fauna off Hutchinson Island, whether the smallest plant or the largest fish, are intricately interrelated. Additional, and often more specific, trophic interrelationships will be discussed in following sections of this report.

IMPINGEMENT

Materials and Methods

The intake structure consists of four bays, each with a bar cityy grill, a traveling screen, a circulating water pump, and auxiliary

equipment. Pumps at the intake structure provide a total maximum

flow of 2 x 106 liters/min (5.3 x 10s gal/min). The approach velo-

to each bay is approximately 30 cm/sec (1 ft/sec; FPL, 1971).

The traveling screens have a mesh size of 9.5 mme (0.4 inz)

Organisms impinged on these screens are washed into a collecting

basin and do not survive.

Impingement sampling was conducted approximately twice weekly.

Each 24-hour sampling period was divided into three consecutive

8-hour segments: 0100 to 0900, 0900 to 1700, and 1700 to 0100 hr.

Data from each time period were analyzed by one-way analyses of variance to determine the significance of diel variations.

Specimens washed off the traveling screens were collected in

a 2.9-ms (3.8-yd ) basket of 9.5-mme (0.4-inz) mesh. Specimens were identified to species, counted, measured to the nearest millimeter, and weighed to the nearest gram. Standard length (SL), the distance from the tip of the snout to the base of the tail, was measured for most fishes. Total length (TL) was measured for fishes with indis- cernible tail fins. Carapace (shell) length was measured for shrimp and lobster; carapace width was recorded for crabs. Although fishes and shellfishes were often individually weighed and measured, these were combined in the Appendix tables to form broad size classes within each species and reported as the number of individuals, range of standard lengths and total weight.

On the few occasions when several hundred individuals of the same species were found (e.g., anchovy and tomtate), a representative aliquot was generally taken. Ten to 25% of the specimens were counted and weighed, the range of lengths was recorded and then all the individuals were weighed. The total number of individuals was calculated by:

W N = —xN) W)

where: N = total number of individuals

W = total weight

Ny = number of indi vidual s in al iquot

= W> al iquot wei ght l The taxonomic nomenclature for fishes was in accordance with

Bailey et al. (1970), with the exception of a few changes made in more recent literature.

Only the shellfishes of cormercial importance were considered for this report. These were shrimp (penaeus spp., rrachypenaeus spp. and sicyonia spp.), blue crab (ca12inectes spp.), stone crab (beni ppe

IN rcenaria) and spiny lobster (panulirus argus) .

The species data detailed in the Appendix tables are summarized by category or taxon in the text (both for impingement data and those collected by other methods). Categories or taxa are groups of closely related fishes. These are generally fishes of the same species, genus, or family, although closely related families (e.g., the three families comprising the flatfish taxon) were also combined on occasion.

Results and Discussion

A total of 98 samples was collected and analyzed during 1977. a Sampling time comprised 28.95 of plant operation time during the year. The results of each sample include the number of individuals, length ranges and weight for each species collected duri ng the three diel time periods, and are presented in the Appendix (Tables J-1 through J-98). These data are summarized in Table B-l. a 98 24-hr sam les 339 days per yr on- ine

Fish

Fishes were collected during almost every sampling period and averaged 223 individuals and 2.7 kg (6 lb) per day. Impingement rates were low (<50 fish per day) at the start of the year, increased in

February and March, and then declined for most of May through July

(Figure B-l). The highest number of fishes (7567) for a single day was impinged in late August. The number of fishes collected then decreased through September and was usually less than 100 individuals per day through the remainder of the year.

Impingment rates based on biomass (kg per day) coincide with rates based on the number of fishes,, with the exception of May through early June samples (Figure B-2). Samples during this time each included from one to 15 crevalle jack. These fishes ranged in size from

235 to 407 mm SL and averaged about 800 g (1.8 lb) in weight. In other words, fish biomass was high relative to the number of individuals found. This species will be further discussed elsewhere in this section. I

Based on a sample size of 28.94, the extrapolated total fish

impi ngement during 1977 was 74,754 individuals and 915 kg (2015 lb).

The extrapolated total fish impinged during 1977 would have been 80,612

individuals and 987 kg (2171 lb) if the plant had been on-line 365 days a (sample size = 26.8X). For comparative purposes , the commercial t

Although very few conmercial species were found during impingement sampling, comnercial landings data are available and provide a means of placing the biomass of impinged fishes in perspective. I landings of finfish on Florida's east coast totaled 15.8 million kg (34.8 million lb) in 1975, the latest year for which landings data are avai lable. Fish caught in Martin and St. Lucie Counties comprised about 3.5 million kg ( 7.8 million lb) of this total (NOAA, 1977) .

The predominant fishes collected during impingement sampling were members of the grunt (Pomadasyidae) and anchovy (Engraulidae) fami lies, based on the numbers of individuals collected. Based on biomass, the predominant fishes were jack (Carangidae) and grunt.

The grunt family comprised 50.35 of the total number of fishes

a collected and 31.15 of the biomass (Table B-2). Although nine species of grunt have been collected in the vicinity of the St. Lucie Plant, the tomtate (aaemuIon aurolineatum) is by far the most abundant.

This species is common i n the neritic zone, on offshore reefs and surf-zone reefs; it is of frequent occurrence around inlets and on the grass flats in the Indian River (Gi lmore, 1977). Tomtate feed on annelid worms, molluscs, crustaceans and some small fish (Bohlke and Chaplin, 1968). Although of forage value, its maximum size is only about 230 mm (9 in), and it is not of sport or comnercial importance.

The tomtate was the most abundant species in the impingement

samples, and accounted for over 995 of the catch on 29-30 August, when the largest amount of fishes was found ( Figures B-1 and B-2) . II This high rate of tomtate impingement was coincident with a temporary increase in the rate of chlorination from 682 kg per day to 1136 kg per day (1500 to 2500 lb per day). Corrective measures (i.e., monitoring of the intake screens and residual chlorine levels) have since been initiated when increased chlorination was necessary, and no comparable impingement rates have occurred.

Anchovies comprised 28.05 of the total number of fishes collected but, because of their relatively small size, only 3.1/ of the total biomass (Table B-2). Seven species of anchovy have been found in the vicinity of the St. Lucie Plant (Appendix Table J-lA), although only the longnose, bay and Cuban anchovies (mchoa nasuta, a. mi tchilsi and a. cubana, respectively) are particularly abundant. Anchovies were very abundant during the early part of the year and accounted for the numerical peaks seen in February and March (Figure B-1). They are common to abundant in the neri tie zone, surf zone, open sand bottom and in the Indian River over the grassflats and around mangroves.

The bay anchovy is even found in freshwater tributaries and canals (Gilmore, 1977). These species are not directly used by man, but, because of their abundance and wide habitat distribution, are of major importance as forage for the larger food and sport species.

Jacks accounted for only 4.75 of the total number of fishes collected but wer e the predominant taxon based on biomass (40.9X);

(Table B-2). This is a large family of fishes and 16 species have been collected in the vicinity of the plant (Appendix Table J-lA).

The vast majority of jacks in the 1977 impingement samples were the previously mentioned crevalle jacks; second most abundant were the

Atlantic bumper (chloroscombrus chrysurus). The commercially important Flolida pompano (Trachinolus carolinus) is also a member of this family; although fairly common in the surf zone, only one Florida pompano was found in the impingement sampling.

The crevalle jack and Atlantic bumper are common in the neritic and surf zones, on inshore and offshore reefs, over open sand bottom, and in the Indian River around inlets and grass flats (Gilmore, 1977).

These predaceous species are not considered food fishes or of commercial importance. The crevalle jack is of limited importance as a sport fish because of its fairly large size and fighting ability.

Fishes other than grunt, anchovy and jack occurred in relatively low numbers. No other group of fishes individually comprised over

6.6X of the total number of fishes collected or 3.7Ã of the biomass

(Table 8-2). Few sport or coranercial fishes were found.

Among the sport or commmercial fishes were the drum (Sciaenidae), represented by seatrout and spot in the impingement samples. Sil ver seatrout (cynoscion nothus) were represented by 38 individuals, mostly found in January through March. Two weakfish (c. regales) were also found. The spot (reiostomus xanehurus) was represented by nine individuals in the sampling. The spotted seatrout (c. nebuIosus), an important food and sport fish common in the adjacent Indian River, has not been found in the impingement samples, nor in'ceanic sampling by other methods (e.g., gill net). The red drum and black drum (sciaenops ocellata and zogonias cromis), also important sport fishes in the Indian River, were not collected.

Sport or commercial fishes other than drum included snapper with 10 individuals (primarily lane and yellowtail snapper) found during all impingement sampling periods, mullet (9 individuals), great barracuda (7), and Fl ori da pompano (1) . It i s of impor tance that no snook, cobia, grouper, bluefish, billfish, king or Spanish mackerels were collected during the impingement surveys, although these species were known to occur offshore or in the surf zone.

The diel studies, conducted to determine if differences occurred between daytime and nighttime impingement rates, indicated, that a mean of 37 fish per 8 hr were collected from 0100-0900 hr, 157 fish from

0900-1700 hr, and 27 fish from 1700-0100 hr. Although differences between time periods were not statistically significant (a=0.05) due to considerable variations within each time period between days sampled, more fish were impinged during the day (0900-1700 hr). This may be the result of differences in diel acti vity patterns of the fish (i.e., increased activity during the day), although plant-related effects, such as daytime chlorination, cannot be eliminated from consideration.

Comparison of the 1976 and 1977 impingement data was somewhat limited because of differences in plant operation mode. The plant was not on-line until April 1976 and was off-line during most of

August and September, when the peak impingement rates were recorded in

1977. However, the two high impingement periods recorded in 1976

(Hay and October) did not recur in 1977. This indicates peak impingement rates may be isolated events rather than seasonal phenomena.

Based on sample sizes of 23.4 and 28.9/ for 1976 and 1977, respectively, extrapolated total impingement while the plant was on-

line was about 69,000 fishes in 1976 and 74,800 in 1977. Extrapolated total impingement if the plant had been on-line 365 days each year was about 131,100 fishes in 1976 and 80,600 in 1977 (sample sizes

of 12.3/ and 26.8/, respectively).

Based on the same sample sizes, the extrapolated total fish bio-

mass was about 230 kg (506 lb) in 1976 and 915 kg (2015 lb) in 1977

while the plant was on-line; and 437 kg (961 lb) in 1976 and 987 kg

(2171 lb) in 1977 if the plant had been on-line 365 days each year.

The above extrapolations indicate that impingement rates based

on the number of fishes decreased from 1976 to 1977 while impingement

24-hr sam les 45 x 100 192 ays per yr on- ine l I rates based on fish biomass increased from 1976 to 1977. These differences between the two years are explained by the relative abundances of the different taxa making up the samples. Large numbers of small species, such as anchovy and Atlantic bumper, were predominant in the 1976 samples, while smaller numbers of generally larger species, such as tomtate and crevalle jack, predominated in 1977.

The variations in the relative abundances of the taxa could be due to large populations of certain species (particularly anchovy) in the intake canal prior to the plant's going on-line in 1976. The high populations could have occurred during canal construction when access was available from the surf and the Indian River. This concept of high populations and subsequent impingement when the plant went on-linetivelyy is hypothetical; however, it is somewhat supported by the large anchovy impingement in 1976, which did not recur in 1977. If, i n fact, an initial accumulation of fishes had occurred, the compara- higher number of fishes impinged in 1976 should not,recur.

Shel 1 fish

A total of 7202 commercially important shellfishes weighing 30.8 kg (68 lb) was found during impingement sampling (Table B-2). Shrimp comprised 88.7Ã of the total number of shellfishes collected and 42.1/ of the biomass. Blue crabs accounted for 10.1% of the number of shellfishes and 54.9Ã of the biomass. Stone crab and spiny lobster together comprised only 1.2 and 3.0A by number and biomass, respectively. I Shrimp (primarily penaeus spp., although Trachypenaeus spp. and sicyorua spp. were also included) were collected during almost every sampling period (Figure B-3) and averaged 65 individuals and 132 g per day. Based on a sample si ze of 28.9Ã, the extrapolated total shrimp impinged while the plant was on-line during 1977 was 22,110 i ndi viduals wei ghing approximately 45 kg (100 lb) . Extrapolated shrimp impingement would be 23,840 individuals weighing 48 kg (106 lb) if the the plant were on-line 365 days. For comparative purposes, the commercial landings of shrimp on Florida's easy coast totaled 1.2 million kg (2.6 mi llion lb) in 1975 (NOAA, 1977). Although only 2600 kg (5800 lb) of shrimp were recorded from St. Lucie County and none from Hartin County in 1975, the wide-ranging shrimp boats operate off this area and land their catches elsewhere.

An average of 37 shrimp per 8 hr was found during the 0100-0900 hr period, 4 during 0900-1700 hr, and 22 during 1700-0100 hr. A si g- nificantly (n=0.05) higher number of shrimp were impinged during the 0100-0900 hr period than during the 0900-1700 hr period. Differences between other periods were not significant (a=0.05). Juvenile and adult penaeids are omnivorous bottom feeders and are generally most active at night (Eldred et al., 1971; Calder et al., 1974) . These diel activity patterns account for the larger numbers of shrimp being collected at night in the impingement samples. b See Eldred et al. (1961) and Joyce and Eldred (1966) for pertinent references regarding this important resource.

B-20 t Blue crabs (callinectes spp.) were collected during 885 of the sampling periods (Figure B-3) and averaged 7.4 individuals and 173 g per day. The extrapolated total blue crab impinged during 1977 was

2516 individual s wei ghing about 59 kg (130 lb) while the pl ant was on-line, and would have been 2713 individuals weighing 63 kg (139 lb) if the plant had been on-line 365 days. Commercial landings of blue crab on Florida's east coast totaled almost 1.9 million kg (4.2 million lb) in 1975. About 2900 kg (6300 lb) were reported for Martin and St.

Lucie Counties (NOAA, 1977).

Stone crab (Henippe mercenaria) and spiny lobster (aanulirus argus) impingement rates were low, each ranging from 0 to 3 individuals per day (Figure B-3). Totals of 59 stone crabs weighing 710 g and 26 spiny lobster weighing 227 g were collected during the year's sampling.

These crustaceans were mostly juveniles and, being secretive in behavior, may have entered the intake seeking shelter. Stone crab and spiny lobster are commercially harvested in Martin and/or St. Lucie Counties, although the combined landings of these shellfishes are only about 0 .3/ of the Florida east coast total.

Impingement of commercially important shellfishes was similar during 1976 and 1977 studies in that shrimp had the most individuals impinged, then blue crab, stone crab and spiny lobster. Blue crab,

then shrimp, were the most abundant each year based on biomass . How- ever, the relative abundances of these four taxa varied between 1976 I and 1977, particularly for shrimp and blue crab (Table B-2). These differences may be due to natural yearly variations or to the plant being off-line 'during most of July, August and September 1976, when large numbers of shrimp (relative to blue crab) were found in 1977, However, it can only be surmised that shrimp impingement would have '\ been high during July through September 1976 had the plant been on-line.

INSHORE CANAL GILL NETS

Materials and Methods Monthly gill net collections were taken at Stations 13 and 15 in the intake canal and Station 16 in the discharge canal (Figure B-4).

More intensive effort in the intake than in the discharge was to determine if fishes were accumulating in the intake canal due to entrapment a at the intake velocity cap. Station 14 was not sampled after March, when results (from 1976) indicated that sampling two stations near the same location was an unnecessary duplication of effort.

The gill nets measured 30.5 m in length by 3 m in depth (100 x 10 ft) and consisted of two 15-m (50-ft) panels of 38- and 51-mm (1.5- and 2-in) stretch mesh sewn end-to-end. One net was fished at the surface and one net at the bottom at each station. The nets at each station were fished at mid-canal and approximately 6 m (20 ft) apart to prevent en'tanglement (Figure B-5). Sampling duration was two consecutive 24-hour periods.

Station 16 was inadvertently omitted in March instead of Station 14.

B-22 I Fishes were removed from the nets and analyzed after each 24-hr period. Analyses were by the same methods described under Impingement,

Materials and Methods.

Results and Discussion Data col-lected during gill netting in the intake and discharge canals are summarized in Table B-3. The data by sampling period include the length ranges and total wei ght by species collected and are compiled in Appendix Tables J-99 through J-122. Four shellfishes were taken from the intake canal during these collections (one each of blue crab, speckled crab, shameface crab and spiny lobster) . No shellfishes were collected from the discharge canal.

A total of 401 fishes was collected from the intake canal, and one from the discharge canal, during the 12 months sampled (Table B-4).

No single species or taxon was particularly dominant relative to the others (Table B-3). Atlantic spadefish comprised 21.05 of 'the catch, followed by jack (13.95), snapper (12.2X), porgy (11.7Ã), and grunt (10.2/). Other taxa collected each comprised less than 9/ of the catch. These were mostly sharks and rays, mojarra, drum and mullet. Of particular significance is that no Spanish macker'el or bluefish were found. These important sport and commercial species together comprised 60/ of the fishes collected by gill netting offshore (Table B-6), but they apparently avoid entrapment at the intake. I

II The collection data from the canal gill nets also indicate that certain taxa may become entrapped without necessarily becoming impinged.

This appears to be the case for the sharks and rays, snapper, spadefish and mullet, all of which were represented by more individuals in the gill net collections than in the impingement collections.

The rate of capture, calculated as the number of fishes per net per 24 hours, was plotted for the last two years to determine if fishes were accumulating in the i ntake canal ( Figure B-6). The catch per unit effort (CPE) was quite erratic but remained below 5 fish per net per 24 hours until April 1977. The CPE reached almost 6 on this occasion and then dropped back below 5 until November. In November the CPE climbed to 13.4, then dropped back below 5 in December.

Linear regression analyses yielded a line which showed a gradual increase in the CPE from October 1976 (when the plant was more or less consistently on-line) to December 1977 (Y=2.28 + 0.18X; Figure B-6). This slope appears unrealistic because of the unusually high number of fishes collected in November 1977. Because the CPE was again below 5 in December, no particular significance was attributed to the high November catch. Exclusive of the November sample, the slope of the line (Y=3.47 - 0.06X) indicates a slight decrease in the CPE since October 1976.

B-24 II

~ The taxa found during the 1977 inshore gill net survey were basically the same as those found during 1976, although the percentage composition of the different taxa varied (Table B-4). Spadefish made up 21% of the catch in 1977 and less than lX in 1976. On the other hand, drum and mullet were the numerically dominant fishes in 1976 (25 and 20$ , respectively) and comprised only 6 and 7X of the catch in 1977. Other taxa also varied but not to the extent of the above-mentioned species. Although differences in percentage composition resulted, at least in part, from the presence or absence of schooling species, any si gni ficance of these differences is not known.

The offshore inlet of the intake pipe is equipped with a velocity

cap to maximize a horizontal direction of approach to the intake.

Fishes are more likely to detect and avoid a horizontal flow, whereas

they may become entrapped by a downward flow. As determined from canal gill net (and impingement) studies, the velocity cap appears to vary from being extremely effective in excluding some species (e.g.,

pompano, Spanish mackerel, and bluefish) to being of limited effect in excluding others (e.g., crevalle jack). However, if the previously hypothesized concept of high initial fish populations in the intake canal (resulting from access to the surf and the Indian River during construction) is correct, then the velocity cap might be more effective than the gill net and impingement data indicate.

B-25 I OFFSHORE GILL NET

Materials and Methods

Monthly gill net collections, were made at each of six offshore stations. Stations 1 through 5 were in the vicinity of the plant and

Station 0 (control) was located to the south (Figure B-7). The offshore gill net measured 183 m in length by 3.7 m in depth (200 x 3 yd) and was made up of five 36.6-m (40-yd) panels sewn end-to-end. The mesh si ze of the panels varied, measuring 64-, 74-, 84-, 97-, and

117-mm (2.5-, 2.9-, 3.3-, 3.8-, and 4.6-in, respectively) stretch length. The net was fished on the bottom, perpendicular to shore, for 30 minutes at each station.

When large numbers of fishes were encountered, net retrieval was time-consuming, and the part of the net remaining in the water continued to catch more fish.'uring these months (January and Octo- ber), fishing time at subsequent stations was reduced to 10 minutes.

The catch data were adjusted to 30 minutes fishing and 10 minutes

retrieval time, based on the actual time of oper ation recorded, to maintai n uniform data presentation.

Specimens collected by gill netting offshore were analyzed by

the same methods described under Impingement: Materials and Methods.

Data by month and station were analyzed statistically by two-way

analyses of variance. When significant differences occur red, Tukey's

HSD (honest significant difference) comparison was used to identify

which means were significant. B-26 I

I Results and Discussion Data recorded during offshore gill netting surveys are summarized in Table B-5. Specific length and weight data, by station and month, are included in the Appendix (Tables J-123 through J-134).

A total,,of 1223 fishes was collected by this method during the

12 months sampled (Table B-6). Spanish mackerel and bluefish together comprised over 60% of these fishes. Three species of jacks accounted for over 23% of the fishes collected. All other species combined accounted for only a little over 16% of the total.

The largest total number of fishes (351) was collected from

Station 1 (Figure B-7), near the point of discharge; closely followed by the number (305) collected at Station 0, the control; and Station

2 (304 fishes), the location directly out from the discharge. Although considerably fewer fishes were found at Stations 3, 4 and 5 (10 to 198; Table B-5), differences between stations were not significant (a=0.05) because of wide variations within each station between the different months sampled. There were, however, differences in the number of fishes collected between months for all stations combined. More fishes were collected in October than in any other month and, with the exception of January, the differences were significant (a=0.05).

There were no significant differences when other months were compared.

B-27 I

I Differences between the numbers of fishes collected at the different stations, and during different months, was primarily attributed to chance. That is, the taxa involved were mostly highly mobile schooling species, often migratory, and the data obtained during offshore gill netting probably reflect the fortuitous occurrence (or non-occurrence) of these fishes.

Differences between the numbers of fishes collected at the different stations could also be attributed to the station's location offshore. For example, if the forage species were most abundant near shore, they would attract the larger predators to the nearshore locations. The nearshore location of the discharge (Station 1) could explain the larger number of fishes collected there. Additionally, bottom relief provided by the discharge pipe, warmer water or turbulence at this location may attract the forage fishes and, in turn, the larger predators. However, when the actual numbers of fishes are compared, and considering the lack of statistical differences between stations, the number of fishes collected in the discharge area did not appear excessive.

The Spanish mackerel (scomberomorus maculaeus) comprised 33/. of the fishes collected during offshore gill netting (Table B-5). Most

Spanish mackerel were collected in October, which is the time of south- ward migration. The largest number of individuals (240) was found at Station 2. Although considerably fewer Spanish mackerel were found I

I I at the other stations (including the discharge area), differences between stations are not significant (a=0.05) because of wide variations within each station.

The Spanish mackerel is a migratory species which moves north in the spring, spawns during the summer months in the northern part of its range (north of Cape Canaveral on the Atlantic coast), and migrates south in the fall (Wollam, 1970). Movements of these fishes are generally near shore, as evidenced by operations of the commercial fishermen. Commercial landings in 1975 in Martin and St. Lucie Counties totaled almost 1.5 mi lion kg (3.2 million lb), which represented 62K of the entire landings on Florida's east coast (NOAA, 1977).

King mackerel (scomberomorus cavalla) were found only in October.

Seventeen individuals were found at the control (Station 0) and 10 were found just south of the plant (Station 4). The king mackerel is very similar to the Spanish mackerel in its migratory habits; it moves north in the spring, spawns in the summer months north of Cape Canaveral on the Atlantic coast, and moves south in the fall (Wollam, 1970). In addition to its commercial importance (0.8 million kg or 1.8 million lb landed in Martin and St. Lucie Counties in 1975), this species is considered the most prominent marine fish in the sport fishery in Florida (Beaumariage, 1973). This species generally occurs farther offshore than the bluefish and Spanish mackerel, as evidenced by the

B-29 I

I I I I I I I I

I comparatively low number of individuals in our gill net collections. It is doubtful that plant operations would influence the movements of this species.

The bluefish (pomatomus saltatrix) comprised 274 of the fishes collected by offshore gill netting. The majority (92/) of the bluefish were found in January (Table B-5). The highest number (175) of bluefish was taken in the area of the discharge (Station 1) and the second highest (140) at the control area (Station 0). Considerably fewer bluefish were found at the more offshore stations. Because the bluefish were found during only three months and varied widely in abundance, differences between stations and months are not significant (a=0.05).

Bluefish occur in the winter off the St. Lucie area. Northerly movement occurs during spring and summer (Beaumariage, 1969) and spawning occurs in offshore waters north of Florida in early surfer (Deuel et al., 1966). Northward movement along the Florida coast is probably part of a spawning migration by that part of the population that extends its winter range into south Florida waters (Moe, 1972).

This species is also of sport and commercial importance, a total of

242,000 kg (533,000 lb) being landed in Martin and St. Lucie Counties in 1975 (NOAA, 1977).

B-30 I

I I I I

I Most of the fishes collected other than mackerel and bluefish were jacks (family Carangidae). The most common jack collected was the Atlantic bumper, which comprised 17.25 of all fishes found (Table

B-5). Other jacks found were blue runner, crevalle jack, banded rudderfish, Florida pompano, round scad and Atlantic moonfish. The only coranercially important jack was the Florida pompano. Only five pompano were found and all in October: three in the area of the discharge (Station 1) and two north of the plant area at Station 5.

The only other fishes of sport or comercial importance found during gill netting operations were 33 spot and 12 menhaden. The spot (reiostomus xantburus) were almost all found in August south

of the plant at Station 4. The menhaden (Brevoortia spp.) were mostly found in January and October north of the plant at Station 5.

During both 1976 and 1977 studies, the largest numbers of fishes were collected in October. The largest percentages of fish were

collected at Station 1 in the vicinity of the discharge during both years, although the percentage catch at this station was lower in

1977 than in 1976 (29 vs 475). This decrease was attributed to large

numbers of crevalle jack at Station 1 during November and December of

1976, whi ch di d not recur i n 1977.

Spanish mackerel and bluefish comprised higher percentages of the offshore gill net catch in 1977 than in 1976 (Table B-6). Jacks,

8-31 I I I

I I I

I I

I on the other hand, were more abundant in 1976. Little importance is placed on these differences, primarily because of the fortuitous occurrences of the taxa involved. However, this is not meant to rule out natural fluctuations in abundance, which could also alter species

relative abundance. For example, there was considerably more activity

"by coranercial. mackerel fishermen in 1977 than in preceding years and large catches were indicated, although landings data are not yet

available. Changes in species'er centage composition were not

attributed to any plant-related effects.

TRAML

Materials and Methods Monthly trawl samples were taken at each of six offshore stations

(Figure B-7). One 15-minute tow was made at each station with a 5-m (16.5-ft) semi-balloon bottom trawl of 12.7-mm (0.5-in) stretch mesh

in the bag and 6.4-mm (0.3-in) stretch mesh in the cod end. Towing

speed was 2-3 knots at each station. All trawling was conducted at

night to reduce net avoidance by the fishes.

Fishes collected by trawl were analyzed by the same methods described under Impingement: Materials and Methods. Data by month

and station were analyzed statistically by two-way analyses of variance.

Macroinvertebrate samples were obtained concomitant with the fish

samples and are discussed in Section C.

8-32 Results and Discussion

Numbers of fishes collected during trawling surveys are given

in Table B-7. Specific length and weight data, by station and month, are included in Appendix Tables J-135 through J-146.

A total. of 2048 fishes were collected by this method during the

12 months sampled (Table B-7). Drum, which include the seatrout,

accounted for almost 42K of the fishes found. The flatfish taxon

sole and tonguefish) comprised almost 11Ã of the fishes 'flounder,

found. All other fishes each comprised less than 95 of the total.

The largest number of fishes (1049) was recorded at Station 1, the discharge area. Eight hundred twenty-four (824) of these fishes,

or 79K, were found in the November trawl sample (Table B-7). Host

of the fishes found on this occasion were juvenile (9-28 mm SL) seatrout and other drum. It is not known whether the collection of this

many juveniles in the area was a chance occurrence, or whether they

were attracted to the discharge vicinity.

The next largest number of fishes (339) was found north of the plant at Station 5; then Station 0, the control area (250 fishes);

the two stations (2 and 3) farther offshore from the discharge area

(175 and 127 fishes, respectively); and the area south of the plant

at Station 4 (108 fishes). The differences in the numbers of fishes between stations are not statistically significant (a=0.05) because I

I of the wide variations within each station between the different months sampled. Additionally, differences were not significant

(a=0.05) between months for the total number of fishes found at all stations combined.

Two thousand forty-eight (2048) fishes were found during trawling

in 1977 compared to 656 in 1976 (Table B-8). This difference is due primarily to the large number (856) of juvenile drum found in 1977

and partially to the fact that two fewer months were sampled in 1976.

The drum accounted for almost 42% of the fishes found in 1977 compared

to only 2.0Ã in 1976 (Table B-8). Exclusive of drum, the relative

abundances of the different taxa (flatfish, grunt, searobin, sand perch, mojarra, cusk-eel and lizardfish) in 1976 and 1977 were quite

similar. The flatfish, grunt and mojarra enter the commercial landings in Martin and St. Lucie Counties (NOAA, 1977), although they are of minor importance compared to other species.

The differences between the number of fishes collected from March

through December (January and February were not sampled in 1976) during

1 1976 and 1977, both overall and between months, were not significant (a=0.05).

B-34

BEACH SEINE

Materials and Methods

Beach seining was conducted each month at each of three stations: north of the discharge, between the discharge and i ntake adjacent to the plant, and south of the intake (Stations 6, 7 and 8, respectively;

Figure B-7). Three replicate seine hauls were made at each station during each sample period.

The seine was 30.5 m in length by 1.8 m in depth (100 x 6 ft), with a mesh size of 12.7 mm (0.5 in ). It was heavily weighted along the bottom and had extra flotation along the top to maintain a hanging position under surf conditions. The rolled net was carried out to a depth of approximately 1.2 m (4 ft), deployed parallel to shore, and pulled in onto the beach with the ends perpendicular to shore.

Specimens collected by seining were analyzed by the same methods described under Impingement: Materials and Methods. Data, by month and station were analyzed statistically by two-way analyses of variance. / When significant differences occurred, Tukey's HSD (honest significant

difference) comparison was used to identify the means that were significant.

Results and Discussion

The total numbers of shellfishes and fishes collected during

beach seining surveys are presented in Table B-9. Specific length and weight data, by station, replicate and month, are included in Appendix Tables J-147 through J-158.

B-35 I

I I I A total of 819 fishes was collected by this method during the

12 months sampled (Table B-9). Sand drum, kingfish and herring each comprised about 21K of the fishes collected. All other fish taxa each comprised less than 104 of the total. The speckled crab, a non-cormercial species, was the only shellfish found.

The largest number of fishes (476) was found north of the plant at Station'6. Two hundred twenty (220) fishes were found in the surf adjacent to the plant at Station 7 and 123 were found south of the plant at Station 8. The number of fishes found at Station 6 was significantly higher (a=0.05) than the number found at Station 8.

There was no significant difference (a=0.05) between Stations 6 and

7 or between Stations 7 and 8. The larger number of fishes found at

Station 6 was due, at least in part, to a more regular bottom contour that enabled a more rapid transit of the net to the beach and a conse- quent reduction in the number of fishes escaping capture.

The majori.ty (72K) of the fishes were collected during the summer months of June through September, when 140 to 156 fishes were found each month for all stations combined (Table B-9). From 2 to 64 fishes were found during the other months. Although more fishes were collected during the summer, the monthly (seasonal) differences were not statistically significant (a=0.05). Ã I The only species of major sport or comnercial value found during

beach seining operations was the Florida pompano (rrachinotus carol~nus).

Commercial landings on Florida's east coast amounted to 88,900 kg

(195,500 lb) valued at $ 223,900 in 1975. Landings in St. Lucie and Martin Counties comprised slightly more than half of the Florida east

coast total (NOAA, 1977). This species occurred in the beach seine hauls during most months, although they were never found in large

numbers at any one time. Seven Florida pompano were found north of

the plant, 10 adjacent to the plant, and 5 south of the plant. Juveniles and adults were about equally, represented during the year.

The largest numbers of fishes were collected in the suraner (June

through September) during both 1976 and 1977. The largest percentages

of the total catch were found north of the plant at Station 6 during

both years (56 and 58% during 1976 and 1977, respectively). Station.

7, adjacent to the plant, had 14% of the fishes in 1976 versus 27%

in 1977; and Station 8, south of the plant, had 30% in 1976 versus

15% in 1977. Based on the 1976 data, the increase in abundance of

fishes from south to north in 1977 appears coincidental. However, the fact that the majority of the fishes were found north of the plant during both years would appear to be more than coincidental. The higher abundance to the north may have been a sampling artifact (i.e., resulting from a more rapid transit of the net and fewer fish escaping at this location), or it may have resulted from some factor presently unknown. Regardless, it is doubtful that the thermal plume I would have a limiting influence on fish abundance to the south,

because the prevailing water currents are to the north in the summer, when most of the fishes were collected.

The percentage compositions of the different fish taxa in 1976

and 1977 are shown in Table 8-10. Herring were the predominant fishes

in 1976 . Sand drum, kingfish and herri ng were the predominant fishes

in 1977. Most of these differences in relative abundance are attributed to the fortuitous occurrences of schooling species in the catch.

For example, the herri ng collected in June 1976 at Station 8 and the

andhovies found in July 1976 at Station 6 accounted for 52.6X of all fishes collected during beach seining operations that year. Also in

1976, all but three of the 101 spot collected were found in September;

none were found in 1977. Exclusive of these particular taxa, the relative abundance of the different taxa was very similar between the

two years.

8-38 l ICHTHYOPLANKTON

A number of places along the Atlantic coast are known to be

P used by fishes for reproduction or nursery grounds. These reproduc-

tive areas either constitute a nursery area or are geographically positioned so that the larvae will drift into a nursery area (Cushing,

1975; Marshall, 1966). Many fishes in their developmental. stages are planktonic and are thus limited in their ability to avoid un-

favorable environmental conditions. In addition, the eggs and larvae of fishes have specific environmental requirements, with little tolerance for abrupt physical or chemical changes. Conse- quently, changes in either the location or physical-chemical makeup of reproductive or nursery areas could have a significant effect on ecologically or economically important fishes.

This study was a continuation of research initiated in March

1976. Its purpose was to further document the composition and abundance of ichthyoplankton in the vicinity of the St. Lucie Plant. As with the adult fish study, evaluation of the ichthyoplankton popula-

tions and the potential effects of plant operation required studies of both inshore and oceanic (offshore) areas. Inshore sampling was conducted to evaluate the effects of entrainment,.or passage of ichthyoplankton through the plant. Offshore sampling was conducted to determine if the area near the St. Lucie Plant was used by fishes for reproduction or as a nursery, and if the offshore thermal discharge affected the distribution and abundance of ichthyoplankton.

B-39 1

l Materials and Methods

Ichthyoplankton at Station 11 in the intake canal and Station

12 in the discharge canal and at oceanic Stations 0 through 5 (Figure

B-7) was collected twice a month using two 20-cm diameter, 505'esh . bongo nets (Figure B-8). At each of Stations 0 through 5, nets were

towed just below the surface for 15 minutes at 3.5 to 4.0 knots.

At Station 11 (intake canal), 10-minute step-oblique tows were taken.

At Station 12 (discharge canal), nets were held in place for 10 minutes close to the point of discharge from the plant where the water

first enters the canal. A digital flowmeter (General Oceanics Model 2030) mounted in th'e mouth of each net enabled calculation of the

volume of water filtered. Water column (ms) through the net was calculated by:

Volume (m ) = AVT

where: A = Area of the mouth of the net (m~)

V = Velocity of current (m/sec)

T = Time (sec).

Ichthyoplankton samples were taken during the day. Supplemental

samples were occasionally. taken at night. All specimens retained

in the cod end collecting bucket were washed into jars, preserved in

5Ã formalin solution in the field, and returned to the laboratory for microscopic and statistical analysis. Water temperature, dissolved oxygen, salinity and turbidity were recorded at the time and location of each sample.

B-40 Eggs were counted and their diameters measured. Although herring and anchovy eggs are distinctive, eggs generally were not iden-

tified to taxon, due to the large nmber of fish species in the area and the lack of specific egg descriptions in the scientific literature.

Larval fishes were identified to the lowest taxonomic classification practical, counted and measured to the nearest tenth of a millimeter,

total length. Identification of larval fishes was facilitated by photographing larvae and arranging the photographs in developmental series from identifiable large forms to increasingly smaller and

developmentally earlier stage larvae. Examples of these photographs are shown in Plates 1 through 7.

Although most of these methods were also used during the 1976 study (ABI, 1977), some changes were made in order to sample more accurately the i chthyoplankton populations in the St. Lucie Plant area. These changes included 1) the use of paired bongo nets versus conical plankton nets at all stations, 2) step-oblique tows versus

surface tows in the intake canal, and 3) stationary nets set close to the point of discharge, where the water first enters the canal and is thoroughly mixed, versus surface tows in the discharge canal.

Bongo nets are more efficient qualitative and quantitative samplers than the conventional conical nets for several reasons. The filtration efficiency of bongo nets is higher at the faster speeds (3.5 to 4.0 knots) than that of conical nets (Posgay and Marak, in press). In addition, because bongo nets have no bridle i'n front of the net opening, net avoidance is significantly reduced. The use of paired bongo net collections also provides a check on net obstructions and meter reliability. In theory, paired nets should collect equivalent samples. An analysis of variance indicated no significant difference

(a=0.10) between paired samples for larval or egg captures (Table B-ll).

The use of step-oblique tows instead of surface tows in the intake canal ensures a more representative sample of the ichthyoplankton population in that area. Thus a more meaningful comparison can be made wi th the sample taken at the point of discharge.

Statistical Anal sis

Statistical analyses were performed by procedures of the Statis- tical Analysis System (SAS; Barr et al., 1976). To determine relationships between ichthyoplankton and physical variables, simple correlations, their approximate significance probability, and the number of observations correlated were calculated by use of the

Correlation (Corr) Procedure. The General Linear Model (GLM) Proce- dure was employed to give the regression approach to analysis of variance using class variables to determine overall station and replicate effects. Examples of the variables, class variables and models used are shown in Table B-12. Duncan's multiple range tests were performed by the Duncan Procedure to determine significantly different station means if significant station effects were found at the 0.10 level of significance. Comparisons using the Duncan Procedure were made at the 0.05 level of significance to reveal only strong differences between ichthyoplankton densities.

The data were analyzed for seasonal and station differences.

Collections were grouped as follows: winter samples were from Decem- ber 1976 through February 1977, spring samples from March through

May 1977, summer samples from June through August 1977, and fall samples from September through December 1977.

Results and Discussion

Approximately 400 samples were collected and analyzed during the period from December 1976 through December 1977. The results of each sample analysis include the number of individuals of each taxon, length ranges, the total number of eggs and larvae per cubic meter and water volume (ms) filtered, and are presented in Appendix Tables K-1 through K-25.

Offshore Stations: E s

A Fish eggs were collected during every sampling period and averaged

5.464/m~. Overall, abundance of eggs was highest in late winter and early spring (Figure B-9). The erratic occurrence of eggs during 1977 may be explained by the high species richness in the area, and is indicative of number of species spawning throughout the year, both continuously and seasonally.

B-43 I

I I I I I I I I No significant differences (a=0.1) in egg densities were detected between Stations 0 through 5 (Table 8-13). However, when analyzed by season, significant (a=0.1) differences between stations occurred during the summer (Table 8-14). At this time, Station 0 (control)

had significantly (a=0.05) higher egg densities than all other oceanic

stations (Table 8-15). Since no significant differences in egg den-

sities occurred between Station 1 (discharge) and Stations 2 through

5, it is unlikely that the- difference in egg densities between Sta-

tion 0 and the other oceanic stations indicates thermal effect.

Furthermore, Station 0 is located farther south (Figure 8-7) and may

be influenced by different water currents than Stations 1 through 5.

Of the physical parameters correlated with egg abundance, the correlations with water temperature, dissolved oxygen and turbidity

proved significant (Table 8-16). Egg density was negatively correlated with water temperature and turbidity, and positively correlated with dissolved oxygen. According to Jones (1964), an indirect negative

effect of temperature on egg distributi on and survival could result from the addition of heated effluents which may lower the density of ambient water. This would affect the buoyancy of pelagic eggs and

cause them to sink (deSylva, 1969). This phenomenon would be unlikely in the St. Lucie Plant area since significant differences in egg densities between the offshore stations rarely occurred, and differences in water temperature between these stations for a given sampling period

8-44 II

I I I I

I rarely exceeded 2'C. A more plausible explanation for the negative correlation with temperature and egg density is that more eggs were collected during the cooler months of this study due to increased spawning activity, which is primarily temperature related. The positive correlation between egg density and dissolved oxygen is probably a coincidence rather than cause and effect, since dissolved oxygen was not a limiting factor throughout the year. Reasons for the negative correlation between egg densities and turbidity are not known.

These correlations between egg densities and physical parameters, although statistically significant, do not entirely explain the overall variations in egg densities found during the year.

Comparison of. the 1977 study results with those of the 1976 study shows some agreement in the above correlations and maximum egg densities, and close agreement in the months in which maximum egg densities occurred. During 1976, egg densities were also found to be negatively correlated with water temperature and positively correlated with dissolved oxygen; egg densities and turbidity were not significantly correlated. In 1976 the highest density of eggs (26/m>) occurred in March, whereas in 1977 high egg densities (33/ms) occurred in February

and April.

Offshore Stations: Larvae

Fish larvae, as well as eggs, were collected during every sam- ~ pling period and averaged 0.696/ms. Overall, abundance of larvae was

8-45 I

I I I

I highest in the winter, then dropped in the spring before increasing

again in summer (Figure B-9). Low larval densities occurred in the

fall and early winter of 1977. When compared over the entire year, n'o significant differences (a=0.1) in larval densities were detected

between Stations 0 through 5 (Table B-13). However, when analyzed by

season, significant differences (a=0.1) between stations occurred during the winter and fall (Table B-17). In the winter, the average

larval concentrati on (number/ms) was significantly higher (a=0.05) at

Station 0 (control station) than at Stations 2 and 3, both of which are offshore from the discharge (Table B-18). In the fall, the average ] larval concentration was significantly higher at Station 1, near the

discharge, than at Stations 2 or 4, offshore from the discharge and southtrationssof the discharge, respectively (Table B-18). Additionally, Station 5, located north of the discharge, had average larval concen- significantly higher than Stations 2 and 4, and significantly

lower than Stations 0, 1 and 3. These differences were not attributed to plant operations since no consistent trends were apparent.

Of the physical parameters correlated with larval abundance, the

correlations with dissolved oxygen and turbidity proved significant (Table B-16). Larval density was negatively correlated with dissolved

oxygen and positively correlated with turbidity. As with egg densities, the correlation between larval densities and dissolved oxygen are probably coincidental, rather than cause and effect, as dissolved

oxygen concentrations were not a limiting factor throughout the year. I I I I

I I I

I I I The positive correlation found between larval density and turbidity may be related to net avoidance by the larvae; that is, they may be more capable of avoiding the net in less turbid water. Regardless, the correlations between larval densities and the physical parameters, although statistically significant, do not entirely explain the overall variations in larval densities found during the study.

Offshore Stations: Fish Taxa Re resented

The most abundant larval fish taxa in all seasons were herring and anchovy (Clupeiformes, Tables B-19 through B-22). Figure B-10 illustrates the densities (number of larvae/m~) of clupeiforms at all oceanic stations for each sampling period covered i n thi s report.

High densities of larval clupeiforms occurred in January and June.

Six species of herring and seven species of anchovy were found in the plant area (Appendix Table J-lA). The eggs and larvae of at least three herring species, dominated by menhaden, occurred in the samples. l Menhaden in a gravid or ripe condition (determined by the release of eggs upon gentle squeeze pressure) occurred in the St. Lucie area in

January and June (Table B-23). Other common herrings, like the

Atlantic thread herring and scaled sardine, spawn through most of the year (Houde, 1977a and 1977b; Houde et al., 1974; Richards et al., 1974). Little is known of the spawning areas of the anchovies encountered at St. Lucie, with the exception of the bay anchovy which is an estuari ne or nearshore spawner. Anchovy larvae and eggs were uncommon in the St. Lucie ichthyoplankton collections. Because clupeiform fishes

B-47 are among the most abundant of all fishes, it is unlikely that the St. Lucie Plant is significantly affecting clupeiform fish populations.

Of the 15 species of drum (Sciaenidae) recorded from the St.

Lucie area (Appendix Table J-lA), seven were taken as ripe adults during fall and winter months (Table 8-23). The distribution of drum larvae is illustrated in Figure 8-11. The maximum density was recorded during the summer, although drum larvae were found throughout the year. Spot and Atlantic croaker predominated in the ichthyoplankton samples, but other taxa (seatrout, kingfish, sand drum and either, silver perch or striped croaker) were also collected. These results are compatible with the ichthyoplankton findings of Powles and Stender (1976), who worked from Cape Canaveral, Florida, to Cape Fear, North Carolina.

Spot and Atlantic croaker spawn in the winter in offshore waters.

Their larvae approach the coast as they grow (Fahay, 1975), and use estuaries as nursery areas. Kingfish (zenticirrhus spp.) spawn offshore and use shallow surf zone habitats when young. Seatrout spawn in estuaries or shallow coastal waters, dependi ng on the species, and use a variety of habitats for growth. Juvenile seatrout and other drum, 9 to 28 mm in length, were collected by trawl at Station 1 during November. Apparently the St. Lucie Plant area is used to some extent as a spawning and/or nursery area by these sciaenids, since both larvae and juveniles were collected in the area.

8-48 I

I Sixteen species of jack (Carangidae) have been collected in the plant area (Appendix Table J-lA) of which three (scad, blue runner,

Atlantic bumper) have been found in ripe condition (Table B-23). Jacks were year-round components of the ichthyoplankton (Figure B-12). The predominant larval jack species were Atlantic bumper and palometa. Few scad were taken, and all were postlarvae or juveniles. The larvae of many jacks occur only in offshore waters where spawning occurs, with development proceeding rapidly so that only juveniles and later stages reach coast'al waters (Berry, 1959). Palometa, permit and Florida pompano spawn offshore, with the palometa comparatively rare along the

South Atlantic coast (Fahay, 1975). Our collections at St; Lucie indicate that the Atlantic bumper is an abundant larval jack in the St.

Lucie area, palometa post-larvae are common, and permit post-larvae are relatively uncommon.

Of 13 bothids and two soleids (in all figures and tables these

taxa are reported as members of Bothidae) reported from the St. Lucie area (Appendix Table J-lA), only the spotted whiff and dusky flounder were taken in ripe condition. The characteristics of larval flatfishes are well documented (Futch, 1971; Futch and Hoff, 1971; Gutherz, 1970). Larval flatfish were collected throughout the year (Figure B-13), and the lined sole (~chirus lineatus) was the predominant flatfish found. Late stage larvae of flounder or eyed flounder (Bothus spp.) appeared sporadically in the collections, as did spotted whiff or fringed 4 flounder (citharichyehys spp.) and a species of syacium. One species,

B-49 I I

I I the deepwater flounder (Monolene sessilicauda) has tentatively been identified in ichthyoplankton collections, but has not appeared in other St. Lucie fish collections. It was taken only rarely, and may have been transported inshore with Gulf Stream eddies. Larvae of this species are rare inshore. aothus and syacium are abundant components of the ichthyoplankton in the South Atlantic Bight during much of the year (Powles and Stender, 1976). A more northern study demonstrated that bothids tend to spawn offshore, in a relatively long spawning season, and that temperature is important in triggering flatfish spawning activity (Smith et al., 1975).

Spanish mackerel (Scombridae) have been found in ripe condition in St. Lucie waters from May through July (Table 8-23), indicating that spawning may occur in the vicinity of the power plant; However, the major spawning area of the Spanish mackerel„ appears to be off the Carolinas, with a disjunct spawning population in the Gulf of

Mexico. Spanish mackerel larvae have been found in the eastern Gulf of Mexico, but not off the east coast of Florida (Wollam; 1970).

It should be noted that several important species, such as snook, bluefish and billfish, were not found in the ichthyoplankton collections. Snook (Centropomidae) are important sport fish in the adjacent Indian River lagoon. Larval snook were neither encountered nor expected in our collections because they breed in coastal water at river mouths or sandy passes, typically in brackish areas, with I

I t f I

I I the juveniles occurring in estuaries (Marshall, 1958; Springer and

Moodburn, 1970; Volpe, 1959). Bluefish (Pomatomidae) is an important sport and commercial species which migrates through the offshore

St. Lucie area. The study area is sough of their spawning grounds (Deuel et al., 1966). Billfish (sailfish, marlin, etc.) are primarily important as sport species. The billfish are offshore spawners, and the larvae and young fish remain offshore during development. Deuel et al. (1966) also reported king mackerel larvae offshore from

Florida's east coast, although recently spawned fishes of either mackerel species were not found south of Cape Canaveral on Florida's east coast. The ichthyoplankton collections rarely yielded scombrid larvae. Those that were found (Plate 3) lack the head spine characteristic of king and Spanish mackerel, are not tunas, and probably represent a non-sport species, the frigate mackerel (Table B-23).

Of several leptocephali collected (mostly at night in a supplemental study), no tarpon, bonefish or American eels were found. Host leptocephali were spotted worm eels, with the remainder consisting of ladyfish, congrid eels and a few unidentified species of eels.

Larvae of mojarras (Gerreidae), blennies (Blennidae, which includes members of Clinidae), and cusk-eels (Ophidiidae) were also collected offshore from the St. Lucie Plant area along with sexually mature adults (Table B-23). None of these taxa have any major sport I

I I I I or commercial value. Seasonal variations in densities of these and the other larval taxa collected are shown in Appendix Figures K-1 through K-S.

Offshore Stations: Study Com arisons

The results of this study compare closely with those of the 1976 study with respect to maximum larval densities and composition of the taxa. However, these studies differed in the month in which maximum larval densities occurred and in the correlations of larval densities with physical parameters. In 1976 a maximum density of 3.074 larvae/ms occurred in September, whereas in 1977 a maximum density of 3.560 larvae/ms occurred in January. During both years herrings and anchovies (clupeiforms) were the most abundant larval taxa collected. Blennies, mojarras, drums and jacks commonly occurred in samples collected during

1976 and 1977. In general, the composition of the larval populations in the St. Lucie Plant area has not changed appreciably between these years.

During 1976, larval densities were found to be positively correlated with water temperature and dissolved oxygen, whereas during 1977, larval densities were positively correlated with turbidity and negatively correlated with dissolved oxygen. These differences are probably due to the fact that winter ichthyoplankton samples were not collected during the 1976 study. These additional data may have had a significant effect on the reported correlations for 1976, especially the correlation between larval density and water temperature. In general, single or multiple variable correlations with ichthyoplankton abundance or location have not been very successful (Parsons and Takahashi, 1973).

In a review of the effects of abiotic factors on marine ichthyoplankton,

Lillelund (1965) concluded that abiotic factors had only an indirect effect and that overall effects were complex and probably associated with biotic factors.

Evaluation of Offshore Waters as a Nurser Area

According to Joseph (1973) and Clark (1974), in order for an area to serve as a si gnificant nursery area it must meet three broad criteria:

1. The area must be physiologically suitable in terms of chemical and physical features; 2. It must provide an abundant, suitable food supply with a minimum of competition at critical trophic levels; and

3. It must in some way provide a degree of protection from predati on.

The offshore waters in the vicinity of the St. Lucie Plant are

not typical of a nursery area on the basis of these criteria.

Physical characteristics needed in a nursery area are low or fluctuating salinities, silt-sand-mud bottom, and extensive beds of rooted aquatic vegetation. Chemically, the offshore waters in the St. Lucie Plant are homogeneous with little variation. Physi- cally, the offshore areas are characterized by the presence of relatively constant salinities, shell-hash sediments (Gallagher and Hollinger, 1977), and the absence of significant macrophytic grass beds. I I I I

I I

I Studies on the diet of larval fishes have indicated that small

zooplankters, especially copepod larvae, are the first food source many larval fishes use shortly before or after yolk-sac absorption

(Bainbridge and McKay, 1968; CusIiing, 1959; Lebour, 1921, 1919 and

1918). This period is critical to larval survival because once the

larvae absorb. their yolk-sacs, they die within hours or a few days

if a food source in adequate concentrations is not available. Zooplankton densities in the plant area may be adequate at certain times of the year, but generally were not optimal. These conclu-

sions are documented i n studies by Arthur ( 1977), Houde ( 1977c),

Zaika and Ostrovskaya ( 1972), Blaxter (1963), Lisinvnenko' 1961),

and Nishimura ( 1956).

Little or no protective cover in the form of rooted aquatic plants or bottom structures is found in the plant area. Further-

a diverse community'ore, of subadult and adult piscivorous fishes

were collected in offshore areas in the vicinity of the St. Lucie Plant. Thus, this area does not meet the nursery ground criteria of providing protection from predation.

Although the oceanic habitat in the vicinity of the power

plant is not typical of a nursery area, the area appears to be

sui tabl e for the devel opment of pe 1 agi c eggs and 1 arvae der i ved from pelagic spawners, as evidenced by the common occurrence of l

I clupeid and sciaenid larvae. Generally, pelagic spawners are not dependent upon the protective nature of a nursery area but rely upon their great fecundity to sustai n their numbers.

Inshore Stations

The average densities of fish eggs at Stations ll (intake canal) and 12 (discharge canal) during this study were 0.743 and 0.327 eggs/ms, respectively. The average densities of larvae at intake and discharge canals were 0.033 and 0.017 larvae/ms, respectively.

No significant (a=0.1) differences were found for egg or larval densities between intake and discharge canals. The average densities of eggs and larvae at the intake were comparatively lower than the average densities reported for offshore stations (5.464 eggs/ms and 0.696 larvae/ms), respectively.

The low concentrations of eggs and larvae recorded in the intake canal compared with those at the offshore stations may indicate that the intake pipe is drawing water for cooling from a relatively depauperate area or depth. A second possible cause of the discrep- ancy is collection methods. Step-oblique tows were taken in the intake canal and surface tows at offshore stations'owever, it is unlikely that the magnitude of the concentration differences is adequately accounted for by this procedural difference. The lower concentrations of eggs and larvae in the intake canal may be due to mortality from passage through the pipe or predation in the intake canal. These possible explanations ai.e being investigated. Of the major categories of fish larvae collected at Stations ll and 12, blennies and clupeiforms were the most abundant taxa found in the winter; clupei forms were the most abundant fishes in the spring and summer. Flatfishes were most common in the fall (Tables B-19 through B-22), although they were only occasionally collected and then in very low numbers. Overall, clupeiforms accounted for the bulk of the larval fishes collected at Stations 11 and 12. The entrainment of clupeiforms into the intake canal is not considered to be highly detrimental to the clupeid populations in the plant area because of their high fecundity. and abundance.

Inshore Stations: Entrainment In order to put the impact of entrainment into perspective'ith the offshore body of water, it is necessary to define an offshore boundary of the region from which ichthyoplankton are probably drawn. For this assessment the boundary is located at Station 3. Fish egg and larval populations beyond this boundary are assumed to be unaf- fected by plant operation. The distance between the imaginary offshore boundary and the shoreline is approximately 3500 m, wi th an average depth of 9.2 m for a calculated cross-sectional area of 32,200 m~.

Since ichthyoplankton tows were made near the surface, additional estimates were calculated based on an average depth of 3 m. This assumes that our surface tows represent ichthyoplankton populations

B-56 I

l to at least that depth. With 3 m as the average depth, the cross- sectional area is 10,500 m~. The average current velocity in this region, with a prevailing direction to the north, is approximately

0. 128 m/sec (Envirosphere, 1977) . This value multi plied by the cross- sectional area estimates the volume of water flowing past the plant per second, i.e., 4122 m~/sec assuming an area of 32,200 m~, or 1344 ms/sec assuming an area of 10,500 m . It is then possible to estimate the percentage of fish eggs and larvae drifting past the plant, wi thin the defined region, that are entrained by. the plant.

The following method used to evaluate entrainment was proposed by Goodyear (1977), who established analytical techniques for entrainment in riverine habitats. The following models have been adapted because the offshore area near the St. Lucie Plant is analogous to a riverine situation (i.e., delineated by a definite cross-sectional area and current flow). ~mC xg C ' Percentage Loss = 100 ~r

where: Cr = mean concentration in number/m~ (based on surface tows only) of organisms in a cross section of the river

C = mean concentration of organisms in the intake water p gr = flow in ms per second (cms) past the plant

water f1 ow through the pl ant intake ( cms ) based on Pp ' ,an average of 11 months of plant flow data = mortality rate of entrained organisms (assumed to be 100%, making m = 1.0)

8-57 I

I NOTE: In the following equations, two values are given for both gr and percentage loss. The first value is based on a cross-sectional area of 32,200 m~ and the second [in brackets] is based on a cross- sectional area of 10,500 m~.

For fish egg entrainment:

Cr = 5.464/ms

= Cp 0.743/ms gr = 4122 cms [1344]

gp = 29.62 cms

m =1.0 1.0 x 0.743 5.464' x 29 62 Percentage loss — x 100

= 0.098% [0.301/] For fish larvae entrainment:

Cr = 0.696/ms

= Cp 0.033/ms gr = 4122 cms I1344]

= gp 29.62 cms 1.0 1.0 x 0.033 ' x 29 62 Percentage loss — 100 4122 = 0.034'0.104']

A more conservative estimate is made by setting the value of mCp / Cr equal to 1. Thus, the average concentration of organisms entering the power plant intake is assumed to be equal to the aver-. age concentration of organisms in offshore areas.

B-58 I

I For fish egg entrainment:

Cr = 5.464/ms

C = 5.464/ms P gr = 4122 cms [1344j

gp = 29.62 cms m. = 1.0 1.0 x 5.464 5.464' 29 Percentage loss — x 100 2

= 0.718% I.2.204%] For fish larvae entrainment:

Cr = 0.696

= Cp 0 696 gr = 4122 cms L1344 cms]

= gp 29.62 cms

m = 1.0 1.0 x 0.696 0.696 Percentage loss — '122 x 100

= 0.718% l2.204%j

Regardless of whether the average densities of eggs or larvae in the intake canal were assumed to be equal or not equal to the average egg or larval densities in offshore areas, or whether the cross-sectional area was assumed to be 32,200 m~ or 10,500 m~, the'ercentage loss due to entrainment for eggs or larvae did not exceed 2.2%. However, this figure is conservative and the estimates of percentage loss due

8-59 I I to entrainment were usually less than 1/. These figures are not considered to be a significant proportion of the ichthyoplankton occurring in the vicinity of the St. Lucie Plant.

SUMMARY

The ichthyofauna offshore from the St. Lucie Plant was a transitional assemblage of temperate and tropical forms. Habitats within the influence of normal operations of the St. Lucie Plant included the surf zone, open bottom and neritic zone. The number of fish species found in these habitats is relatively low compared to those of inshore areas of thy Indian River lagoon and oceanic reefs.

The predominant fishes found during impingement sampling were grunt, anchovy and jack. Few sport or commercial fishes were found.

Shrimp and blue crab were the predominant commercially important shellfishes found. The biomass of impinged fish and shellfish was low compared to coranercial landings.

Comparison of impingement data to intake canal gill net data indicated that certain fishes may become entrapped in the intake canal without necessarily becomi ng impinged. Nevertheless, no large accumulation of fishes in the-intake canal was indicated.

The velocity cap appeared to be extremely effective in excluding some species from the intake and of limited effect with others.

8-60 I I I

I None of the migratory species of sport or commercial importance, such as mackerels or bluefish, were found in the intake canal or on the intake screens at the plant.

The largest total number of fishes was found near the point of plant discharge during offshore gill net and trawl collections, although differences in the numbers of fishes collected at the offshore stations were not statisti cally significant. Differences between stations wer e primarily attributed to fortuitous occurrences.

No effects of the offshore thermal plume on the movement of migratory species, which occur primarily in the fall and winter, were apparent.

The majority of fishes sampled by beach seine were collected during the summer. The largest percentage of the total catch was found north of the plant. Although the reason for the higher abundance to the north is not clear, no plant-induced effects were demonstrated.

Ichthyoplankton densities were generally highest in the winter and lowest in the fall. The most abundant larval fish taxon was clupeiform, a group of primarily forage species which are abundant in the area . Differences in ichthyoplankton densities between offshore stations were not attributed to plant operation since no consistent trends were apparent. I

I I I

I The average densities of ichthyoplankton found in the intake canal were lower than those found at the offshore stations. Esti- mates of entrainment loss were low and considered an insignificant proportion of the ichthyoplankton population occurring in the vicinity of the plant.

In general, physical characteristics offshore from the St. Lucie Plant are not consistent with those found in typical nursery areas. Nonetheless, the area appears suitable for the development. of eggs and larvae derived from certain pelagic spawners which rely upon great fecundity, rather than nursery areas, to sustain their numbers.

Changes in the composition and relative abundance of the ichthyofauna and differences in their normal distribution during the last two years were not attributed to any plant-related effects. The impact of the St. Lucie Plant on the populations of fish and shellfish offshore from Hutchinson Island was considered low.

B-62 I I LITERATURE CITED

ABI. 1977. Ecological monitoring at the Florida Power 8 Light Co. St. Lucie Plant, annual report 1976. 2 vol. AB-44. Prepared by Applied Biology, Inc., for.Florida Power & Light Co., Miami.

Anderson, W.W., and J.W. Gehringer. 1965. Biological-statistical census of the species entering fisheries in the Cape Canaveral area. U.S. Fish Wildl. Serv., Spec. Sci. Rept.-Fish. No. 514. 79 pp. Arthur, D.K. 1977. Distribution, size, and abundance of microcope- pods in the California Current system and their possible influence on survival of marine teleost larvae. Fish. Bull. 75 (3): 601-611. Bailey, R.M., J.E. Fitch, E.S. Herald, E.A. Lachner, C.C. Lindsey, C.R. Robins, and W.B. Scott. 1970. A list of common and scientific names of fishes from the United States and Canada, 3rd ed. Amer. Fish. Soc., Spec. Publ. No. 6. 149 pp.

Bainbridge, V., and B.J. McKay. 1968. The feeding of cod and red- fish larvae. Int. Commn. North West Atl. Fish. Spec. Publ. 7(1):187-217.

Barr, J.A. 1976. J.H. Goodnight, J.P. Sall, and J.T. Helwig. The users guide to SAS 76. Sparks Press of Ra 1ei gh. 329 pp. Beaumariage, D.S. 1969. Returns from the 1965 Schlitz tagging program including a cumulative analysis of previous results. Fla. Dept. Nat. Resources Mar. Lab., Tech. Ser. 59. 38 pp. (from Moe, 1972).

Beaumariage, D.S. 1973. Age, growth, and reproduction of king mackerel, scomberomorus cavalla, in Florida. Fla. Dept. Nat. Resources Mar. Res . Lab., Publ. No. l. 45 pp.

Berry, F.H. 1959. Young jack crevalles (caranx species) off the southeastern Atlantic coast of the United States. U.S. Fish Wildl. Serv., Fish. Bull. 59:417-535. Bigelow, H.B. 1925. Plankton of the offshore waters of the Gulf of Maine. U.S. Bur. Fisheries Bull. Vol. 40, Part 2. 509 pp. (cited in Sverdrup et al., 1942) . Blaxter, J.H.S. 1963. The feeding of herring larvae and their ecology in relation to feeding. Calif. Coop. Oceanic Fish Investig. Rep. 10. pp. 79-88.

B-63 LITERATURE C ITED continued

Bohlke, J.E., and C.C.G. Chaplin. 1968. Fishes of the Bahamas and adjacent tropical waters. Livingston Publ. Co., Wyneewood, Pa. 771 pp.

Briggs, J.C. 1958. A list of Florida fishes and thei r distribution. Bull. Fl. State Mus. 2(8):223-318.

Bullis, H.R., Jr., and J.R. Thompson ~ 1965. Collections by the exploratory fishing vessels oregon, silver Bay, combat and J.elican made during 1956-1960 in the southwestern North Atlantic. U.S. Fish Wildl. Serv., Spec. Sci. Rept. 510. 130 pp.

Calder, D.R., P.J. Eldridge, and M.H. Shealy, Jr. 1974. Description of resource. Pages 4-38 in D.R. Calder, P.J. Eldridge, and E.B. Joseph, eds. The shrimp fishery of the southeastern United States. A management planning profile. S. Carolina Mar. Res. Center., Tech. Rept. No. 5. 229 pp.

Christensen, R.F. 1965. An ichthyological survey of Jupiter Inlet and Loxahatchee River, Florida. Unpubl. M.S. thesis, Fl. State Univ., Tallahassee. 318 pp. Clark, John. 1974. Coastal ecosystems - ecological considerations for management of the coastal zone. The Conservation Foundation, Washington, D.C. 178 pp.

Cushing, D.H. 1959. On the nature of production in the sea. Fish. Invest. Land. Ser. 2. Vol. 22, No. 6. 40 pp.

Cushi ng, D.H. 1975. Marine ecology and fisheries. Cambridge Uni- versity Press, London. 278 pp. de Sylva, D.P. 1969. Theoretical considerations of the effects of heated effluents on marine fishes. Pages 229-293 in A. Krenkel and L. Parker, eds. Biological aspects of thermal pollution. Vanderbilt Univ. Press.

Deuel, D.G., J .R. Clark, and A.J . Mansueti . 1966. Description of embryonic and early larval stages of bluefish, somatomus saltatzix. Trans. Amer. Fish. Soc. 95(3):264-271. Eldred, B., R.M. Ingle, K.D. Woodburn, R.F. Hutton, and H. Jones. 1961. Biological observations on the commercial shrimp. penaeus duorarum Burkenroad, in Florida waters . Fl. State Bd. Conserv. Mar. Lab., Prof. Papers Ser. No. 3. 139 pp.

B-64 LITERATURE CITED (continued)

Envirosphere Company. 1977. (Draft) . Predicted thermal plumes for elevated discharge temperatures, St. Lucie Unit 1. Prepared for Florida Power 5 Light Co., Miami, Florida.

Evermann, B.W., and B.A. Bean. 1897. Indian River and its fishes. Rept. U.S. Comm. Fish. 1897:223-262.

Fahay, M.P. 1975. An annotated list of larval and juvenile fishes captured with surface-towed meter net in the South Atlantic Bight during four RV Dol hin cruises between May 1967 and February 1968. NOAA Tec . ep. NMFS SSRF-685. 39 pp.

Florida Power 8 Light Co. 1971. Hutchinson Island Plant unit No. 1: environmental report. Docket No. 50-335, FPL Co., Miami. Futch, C.R. 1971. Larvae of monolene sessi licauda Goode, 1880 (Bothidae). Fla. Dept. Nat. Res., leaflet ser. 4(21):1-14.

Futch, C.R., and S.E. Dwi nell. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. IV. Lancelets and fishes. Fla. Dept. Nat. Res. Mar. Res. Lab., Fla. Mar. Res. Publ. 24. 23 pp. Futch, C.R., and F.H. Hoff, Jr. 1971. Larval development of sgacium papillosum ..(Bothidae) with notes on adult morphology. Fla. Dept. Nat. Res., leaflet serv. 4(20):1-22.

Gallagher, R.M., and M.L. Hollinger. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. I. Introduction and rationale. Fla. Mar. Res. Pub. No. 23. pp. 1-5. I Gilmore, R.G., Jr. 1974. A regional description and checklist of fishes of the Indian River. Pages 119-183 in H.A. Fehlmann, principal investigator. Indian River study: first annual report. Harbor Branch Consortium, Fort Pierce, Fla. 183 pp. (unpublished manuscript).

Gi lmore, R.G., Jr. 1977. Fishes of the Indian River lagoon and adjacent waters, Florida. Bull. Fl. State Mus. Biol. Sci. 22(3):101-147,

Goodyear, C.P. 1977. Mathematical methods to evaluate entrainment of aquatic organisms by power plants. FWS/OBS-76/20.3. U.S ~ Dept. of the Interior Fish and Wildlife Service. Topical Briefs: Fish and Wildlife Res. and Electric Power Generation, No. 3. 17 pp.

B-65 I I LITERATURE CITED (continued

Gunter, G., and G.E. Hall. 1963. Biological investigations of the St. Lucie estuary (Florida) in connection with Lake Okeechobee discharge through the St. Lucie Canal. Gulf Res. Repts. 1(5):189-307.

Gutherz, E.J. 1970. Characteristics of some larval bothid flatfish, and development and distribution of larval spotfin flounder, cyclopsetta fimbriata (Bothidae). Fish. Bull 68(2):261-'283. Houde, E.D. 1977a. Abundance and potential yield of the Atlantic thread herring, opisthonema ogli num, and aspects of its early life history in the eastern Gulf of Mexico. Fish. Bull. 75(3):493-512.

Houde, E. D. 1977b. Abundance and potential yield of the scaled sardine, Harengula jaguana, and aspects of its early life history in the eastern Gulf of Mexico. Fish. Gull. 75(3):613-628.

Houde, E. D. 1977c. Food concentration and stocking density effects on survival and growth of laboratory-reared larvae of bay anchovy ~choa mitchilli and lined sole Achirus lineatus. Mar. Biol. 43: 333-341.

Houde, E.D., W.J. Richards, and V.P. Saksena. 1974. Description of eggs and larvae of scaled sardine, aarengula jaguana. Fish. Bull . 72(4):1106-1122.

Jones, J.R.E. 1964. Thermal pollution: the effect of heated effluents. Chapter 13 in Fish and river pollution. Butterworths, London. Jones, R.S., R.G. Gilmore, Jr., G.R. Kulczycki, W.C. Magley, and B. Graunke. 1975. Studies of the fishes of the Indian River coastal zone. Pages 57-88 in D.K. Young, ed. Indian River coastal zone study: second annual report. Harbor Branch Consortium, Fort Pierce, Fla. 180 pp. ( unpublished manuscript) .

Joseph, E.B. 1973. Analysis of a nursery ground, Pages 118-121 in A.L. Pacheco, ed. Proceedings of, a workshop on egg, larval and juvenile stages of fish in Atlantic Coast estuaries. NOAA, Nat. Mar. Fish. Serv., Middle Atlantic Coastal Fish. Center. Tech. Publ. No. l. 338 pp. Joyce, E.A., Jr., and B. Eldred. 1966. The Florida shrimping industry. Fl. Bd. Conserv. Mar. Lab., Educ. Serv. No. 15. 47 pp.

Lebour, M.V. 1918. The food of post larval fish. Part I. J. Mar. Biol. Assn. U.K. 11: 433-469.

B-66 LITERATURE CITED continued

Lebour, H.V. 1919. The food of post larval fish. Part II. J. Har. Biol. Ass. U.K. 12:22-47.

Leboury M V 1919. The food of post larval fish. Part III . J. Har. Biol. Ass. U.K. 12:261-324.

Lebour, M.V. 1921. The food of young clupeoids. J. Mar. Biol. Ass. U.K. 12:458-467.

Lebour, H. V. 1924 . The food of young herring. J . Mar. Biol. Ass . U.K. 13:325-330. (Cited in Sverdrup et al., 1942).

Lillelund, K. 1965. Effect of abiotic factors in young stages of marine fish. ICNAF Spec. Publ. 6. pp. 674-686.

Lisivnenko, L.N. 1961. Plankton and the food of larval Baltic herring in the Gulf of Riga. Trudy N.-I. Instituta Rybnogo Khoziaistva Soveta Narodnogo Khoziaistva Latviiskoi SSR 3. pp. 105-138. (Fish. Res..Bd. Canada, Trans. No. 444. 36 pp.)

Marshall, A. R. 1958. A survey of the snook fishery of Florida with studies of the biology of the principal species, ceneroponus undeci mavis (Bloch) . Fla. State Bd. Conserv. Res. Ser. No. 22. 37 pp. Marshall, N.B. 1966. The life of fishes. The World Publishing Co., Cleveland, Ohio. 402 pp.

Hoe, H.A., Jr. 1972. Movement and migration of south Florida fishes. Fla. Dept. Nat. Resrouces Mar. Res. Lab., Tech. Ser. No. 69. 25 pp.

Niskirnura, S. 1957. Some considerations regarding the amount of food daily taken by an early post larva of sardine. Ann. Rept. Jap. Sea Reg. Fish. Res. Lab. 3. pp. 78-84.

NOAA. 1977. Florida landings, annual summary 1975. NOAA Natl. Har. Fish. Serv., Current Fish. Stat. No. 6719. 11 pp.

Parsons, T., and H. Takahashi. 1973. Biological oceanographic processes. Pergamon Press, New York. 186 pp.

Posgay, J.A., and R.R. Marak. In Press. The MARMAP bongo zooplankton samplers. Journal du Consei l. Powles, H., and B.W. Stender. 1976. Observations on composition, seasonality and distribution of ichthyoplankton from HARHAP cruises in the South Atlantic Bight in 1973. South Carolina Mar. Res. Cent. Tech. Rep. Ser. No. 11. 47 pp. B-67 LITERATURE CITED (continued)

Richards, W.J., R.V. Miller, and E.D. Houde. 1974. Egg and larval development of the Atlantic thread herring, opisthonema oglinum. Fish. Bull. 72(4):1123-1136.

Smith, W.G., J.D. Sibunka, and A. Wells. 1975. Seasonal distributions of larval flatfishes (Pleuronecti formes) on the continental shel f between Cape Cod, Massachusetts, and Cape Lookout, North Carolina, 1965-66. NOAA Tech. Rep. NMFS SSRF-691. 67 pp.

Springer, S. 1963. Field observations on large sharks of the Florida Caribbean region. Pages 95-113 in P.W. Gi lbert, ed. Sharks and survival. D.C. Heath and Co., Boston. 578 pp. Springer, V.G. 1960. Ichthyological surveys of the lower St. Lucie and Indian Rivers, Florida east coast. Fl. State Bd. Conserv., Mar. Lab. Rept. 60-19. 17 pp. Springer, V.G., and K.D. Woodburn. 1960. An ecological study of the fishes of the Tampa Bay area. Fla. Bd. Conserv. Prof. Pap. Ser. No. l. 104 pp.

Sverdrup, H. U., M.W. Johnson and R.H . Fleming. 1942. The oceans: their physics, chemistry, and general biology. Prentice-Hall, Inc. Englewood Ciffs, N.J. 1087 pp. Volpe, A.V. 1959. Aspects of the biology of the common snook, centropomis undeci mavis (Bloch) of southwest Florida. Fla. State Bd. Conserv. Tech. Ser. No. 31. 37 pp. Wollam,bilityyM.B. 1970. Description and distribution of larvae and early Juveniles of king mackerel, scomberomorus cavalla (Cuvier), and Spanish mackerel, scomberomorus maculatus (Mitchill); (Pisces: Scombridae): in the western North Atlantic. Fla. Dept. Nat. Resources Mar. Res. Lab., Tech. Series No. 61. 35 pp.

Zaika, V.Y., and N.A. Ostrovskaya. 1972. Indicators of the availa- of food to fish larvae. 1. The presence of food in the intestines as an i ndicator of feeding conditions . J . Ichthyol. 12:94-103. Translation from Vopr. Ikhtiol.

B-68 I I

I I I

.I 800

700

600

10,000 99.31 tom ate 500 Cl

5,000 400

C7 300 2,000 92.8X anchovy 82.4X anc y 85.0% to tat 200

1,000 100

500

ca 200

100

JAN FEB MAR APR MAY JUN JULI AUG SEP OCT NOV DEC 1977 Figure 8-1. Rates of impingement: number of fishes collected per hour compared to total flow through the plant in millions of gallons per day, St. Lucie Plant, 1977.

8-69 I% W W W W 8% W %5 800

700

600

500 Cl 50 99.4X to tate 400

300 ™ 20 61.5'4 to tat

200 99.8C crevalle .gack 10 100 u) 5

1.0

0.5

0.2

0.1

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC i 1977 Figure B-2. Rates of impingement: biomass (grams) of fishes collected per hour compared to total flow through the plant in millions of gallons per day, St. Lucie Plant, 1977.

B-70 lM W W Hl IR W & W W 2,000 Shrimp

1,000 ~ ~ ~ ~ ~ ~ ~ ~ ~ Bl ue crab

~ Stone crab

500 k Spiny lobster

200 LLI

100

~ o

~ ~ 50 ~ ~ C) t ~ ~o ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ .~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ 20 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ t ~ ~ ~ ~ ' ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ 10 ~ ~ ~ ~ ~ ~ o t ~ ~ ~ ~ ~" ~ o ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ t ~ ~o ~ o ~ o ~ ~ ~o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~o ~ ~ oo ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ o ~ ~ t ~ ~ ~ ~ oo ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ . ~ ~ ~ ~ ~ 0 ~ ~ oo ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ koo ~ ~ ~ ~ ~ o e e e 'e ego t t ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~o ~ ~ ~ ~ ~ ~ ke~ ~0 8 4 ~ oo0 ko e0k ko 0 hk kkek '.e b k0 0 6 00k 00e oe ~ ~ ~ ~ ~ t JAN FEB MAR APR MAY JUN I JUL AUG SEP OCT NOV DEC 1977

Figure B-3. Rates of impingement: number of commercially important shellfishes collected per day, St. Lucie Plant, 1977. fl

1 l M M W W

)I P 4 'O )6 y p ( (ay i

„! jlj

lOPfVIP tW'

;v.~

Figure B-4. Inshore (canal) gill net stations, St. Lucie Plant, 1977. I I I

I I I 50 FLOAT

SURFACE NET LINES TO SHORE 2 STRETCH MESH

FLOAT WEIGHT

BOTTOM NET

Figure B-5. Diagrammatic view of the inshore (canal) gill nets, St. Lucie Plant, 1977. I

I I I W M M W M W M

8 t4 l4

d 4

2 2919 „. O.l)g89x

0 J F M A M J J A S 0 N 0 J F M A M J J A S 0 N 0 1975 197d 1977 Figure B-6. Inshore (canal) gill net collections: fishes collected per.net per 24 hours from the intake canal, St. Lucie Plant, December 1975-December 1977. I

I I 80 "15 '

-N-

tg I

t I

~ I I

' Q '-: '::, ~,'eg c Qs

7 I W'I~ ~ I II " Qs Q4 ~ I

~ ~ 27 20'—

FPL ST. LUCIE PLANT 'V l~ O

O ~ 0 .Qo

Figure B-7. Locations of fish sampling stations, 1977. I I

I COD END

CABLE TO SURFACE VESSEL

DIGITAl. FLOHHETER

DEPRESSOR HEIGHT

Figure B-8. Diagrammatic view of bongo nets used in ichthyoplankton sampling at the St. Lucie Plant. I

I I 300 000 I I I I I I I & LARVAE I 10.000 0 = EGGS I I I I I I I I 1.00n 4 A I II I I I I I / I H I 0.100 + /' I I I I I I I I

0 ~ 010 I I I I I I I I 0 ~ 001 I

-%0 30 00 0a Iao IS0 100 EI0 200 ZI 0 E~n 3m WS0 auL3AII nAV Figure 8-9. Mean larval and egg densities (number/m') by Julian (calendar) day, Stations 0 through 5, St. Lucie Plant, 12 December 1976 - 5 December 1977. W W W W W W W W W W W W W W W W W

I ICO OOO I I I I I I I I 10.004 + I I I I I 4 I 4 0 3 I 2 ? H I 1.00n I A I N I I I 0 0 I 0 I I I I 3 5 0 2 3 0 / I ? I 2 5 3 I n H I 5 2 I 0 3 0 ~ 100 + 0 3 4 I I I 2 I I 2 0 I 3 I I 4 5 I I 5 2 ? I ? 4 4 4 ? O.nl0 + 0 3 3 I n I 4 I I I I I I 0 ~ 001 +. I e t 4 t + + + ~30 0 30 00 = 90 l?0 150 IIIO 210 240 260 ?90 3?0 354

JULIAN DAY Figure B-10. Density of Clupeiformes larvae by Julian (calendar) day, Stations 0 through 5, St. Lucie Plant, 12 December 1976 - 5 December 1977.

100 000

In.nnn

N I . nnn A

/ n H I 3 0 ~ I nn

I I n n 2 5 I I 4 3 2 I 4 3 4 2 n.nIn n 0 I 5 0 n

n.nnI

+ + 30 0 30 nn - 00 120 150 IAO 21n 2an 2nn 2nn 32n 350

JIILIAN OAY

Figure B-ll. Density of Sciaenidae larvae by Julian (calendar) day, Stations 0 through 5, St. Lucie Plant, 12 December 1976 — 5 December 1977. I I C + II' W I I I I I I I C + 5 I I r I

I I C + 0 I h. O I I I I QJ I I O n. a I C r + 4 I I

I I I C + a I A $- r I I I 5 I QJ I QJ M I I C + IC$ QJ I O O I I I D I I I QJ LA I C I + C r I I I O I I ? I J5 I V'v ~ O + III rI QJ $- I I IQ QJ I I, E I QJ I C r O + 8 I QJ I QJ D c5 I 0 CV I I CA + O I a I I S- I CQ I<5 I Or II, CL I + C I O QJ I I + O ~ r Vl + C C ~ I VI QJ I M I I I I I I + C

+ IA ~ I I C C C O C O O O O O Xl i ?C rwirI 100 F 000

10 F 000

1.000 4 N

I K F 100

0 =- I I I 0 3 5 I 2 5 2 0 ~ 010 2 3 3 5 0 3

5 0 I 0 F 001 4 2 2

+ ef e + tee e t e e+ et 30 30 60 - 90 120 150 180 210 240 260 290 320 350

JULIIN OAY Figure 8-13. Density of Bothidae larvae by Julian (calendar) day, Stations 0 through 5, St. Lucie Plant, 12 December 1976 - 5 December 1977. I

I TABLE B-l

NWBER AND BIOMASS OF SHELLFISHES AID FISHES COLLECTED DURING 24-HOUR INPINGEHENT SURVEYS AT THE ST. LUCIE PLANT 1977

3-4 J 7- Cateoor No. Mt. No. Wt. No. Wt. No. Mt. No. Mt. No. Mt. No. Mt. No. Wt.

shrimp 16 124 8 51 7 92 21 123 6 39 20 77 60 228 143 272 blue crab 10 282 9 48$ 6 203 26 1616 13 693 16 596 8 377 6 368 . stone crab 1 10 1 1 1 24 1 12

spiny lobster 1 2

shark, ray 1 145 - herring 1 1 2 62 11 96 anchovy 2 2 1 1 6 15 75 3 9 catfish 2 109 4 159 4 125 jack. 2 28 1 2 1 7 3 19 21 107 178 1346 145 767 mojarra 2 7 1 1 2 4 7 40 3 77 6 238 grunt 1 5 84 3 2 9 2 17 3 46 4 65 1 19 croaker 29 205 2 46 3 40 7 134 6 166 blenny, goby 1 4 cutlassfish scorpionfish, searobin 1 7 10 1 5 2 98 2 43 1 3 flounder, sole 20 2 31 5 49 5 50 2 14 4 triggerfish, filefish 945 14 1 433 4 77 2 54 1 604 c puffer, trunkfish 1 5 6 68 7 674 other fish 1 21 3 224 8 631 12 627 12 647 total shellfish 26 406 18 549 14 296 47 1739 20 756 38 687 68 605 149 640 total fish 44 1271 14 127 8 177 9 792 8 45 53 1099 240 2760 200 3366 a ~ ~ b Number of individuals. Total weight in grams. Includes fragments. TABLE 8-1 (continued) NUNBER AND BIOMASS OF SHELLFISHES ND FISHES COLI.ECTED DURING 24-HOUR IHPINGEHENT SURVEYS AT THE ST. LUCIE PLANT 1977

31 J I-1FEB - F 14-15 F Mt Cate or No. Mt. No. Mt. No. Mt. No. Mt. No. Mt. No. Mt. No. Mt. No. shrimp 32 99 13 25 45 57 309 1073 111 315 24 27 15 67 17 42 blue crab 7 401 3 102 3 76 8 175 11 353 11 690 5 88 3 91 stone crab 1 1 1 1 1 10 2 3 spiny lobster

shark, ray 1 73 2 1026 1 252 1 530 herring 1 2 2 22 17 221 40 74 64 287 1 1 anchovy 1 8 5 24 2 3 36 110 2011 2394 11 19 686 990 331 487 catfish 1 56 1 32 2 115 4 150 1 29 1 29

5ack 47 800 1 4 64 972 53 796 9 1559 8 1985 mojarra 1 3 3 23 1 2 8 73 grunt 31 1661 2 12 2 15 1 8 croaker 1 21 73 '1901 1 1 2 207 13 1331 5 517 2 254 3 8 blenny, goby 1 3 38 275 1 1 1 1 2 5 1 2 1 4 cutlassfish 1 28 2 770 2 85 scorpionfish, searobin 2 230 5 268 3 339 2 156 flounder, sole 1 5 1 26 3 102 15 272 9 24 4 89 1 26 tr iggerfish, filefish 1 1 19 3408 1 1 3 1100 2 980 puffer, trunkfish 4 341 4 302 3 410 6 417 10 1298 1 89 2 471 other fish 24 963 4 297 30 655 17 992 2 19 4 42 total shellfish 40 501 17 128 49 143 317 1248 122 668 37 720 20 155 20 133 total fish 12 440 249 9745 20 956 185 4056 2168 9508 28 1996 773 4325 352 2558

a ~ ~ b c Number of individuals. Total weight in grams. Includes fragments. I

I I I I TABLE 8-1 (continued) NINBER AND BIOMASS OF SHELLFISHES AND FISHES COLLECTED DURING 24-HOUR INPINGEHENT SURVEYS AT THE ST. LUCIE PLANT 1977

28 FEB-1 MAR 3- Cate or No. Wt. No. Wt. No. 'Mt. No. Wt. No. Mt. No. Mt. No. Wt. No. Mt. shrimp 13 45 24 168 6 64 15 143 18 171 7 43 .7 40 59 342 blue crab 4 380 3 118 5 212 2 118 4 248 3 230 5 141 7 503

stone crab 2 61 1 3 1 2 2 10 2 13 spiny lobster

- shark, ray her ring 84 434 12 89 3 4 295 890 2 11 36 257 31 127 anchovy 539 841 261 374 36 50 1735 2339 14 27 17 37 15 27 49 44 catfish 2 87 jack 8 1356 7 1022 9 3962 39 121 6 2755 7 5078 200 4819 9 890

mojarra 2 ~ 10 1 4 39 1 3 144 708 145 1351 357 2884

grunt 1 37 3 30 1 17 1 4

croaker 3 397 9 1316 1 8 18 712 2 168 4 22 1 18 4 87

blenny, goby 1 1 4 cutlassfish

scorpionfish, searobin 1 4 29 1 5

flounder, sole 1 9 1 21 2 20 6 107 9 168 65 2 47

triggerfish, filefish 1 564 1 37 1 400

puffer, tr unkfish 2 38 2 23 1 22 44 1 19

other fish 5 87 1 13 2 3 6 364 4 50 6 116 4 8 495

total shellfish 19 486 28 289 12 278 17 261 24 429 10 273 13 182 68 858 total fish 642 3134 293 3403 55 4106 2105 4523 38 3163 193 6253 412 6635 464 5002

a Number of individuals. Total weight in grams. I

I I

I I I I TABLE B-1 (continued) NUMBER ANO BIOMASS OF SHELLFISHES AID FISHES COLLECTED DURING 24-HOUR IMPINGEMENT SURVEYS AT THE ST. LUCIE PLANT 1977

28-29 HA Cate or No. Mt. No. Mt. No. Mt. No. Mt. No. Mt. No. Mt. No. Wt. No. Mt shrimp 19 128 2 3 33 121 8 8 13 23 8 16 7 ~ 14 3 5 blue crab 2 364 3 94 12 535 2 147 11 158 9 108 2 52 1 4 stone crab 2 3 3 12 1 74 1 16 ------1 2 spiny lobster shark, ray herring 2 6 1 6 anchovy 5 8 9 17 9 16 catfish 1 52 jack 2 823 4 1133 9 3017 14 1974 1 773 2, 488 mojarra 74 655 59 328 269 2049 61 299 19 42 grunt 1 6 3 44 1 6 1 97 croaker 3 10 1 6 blenny, goby 1 2 4 30 cutlassfish scorpionfish, searobin 1 44 3 64 3 12 2 14 13 flounder, sole 5 91 18 290 8 52 6 12 15 119 10 4 5 triggerfish, filefish 2 388 puffer, trunkfish 1 20 2 25 2 30 1 136 other fish 2 19 3 8 61 1195 33 778 19 135 19d 24 2 173 total shellfish 23 495 8 109 46 730 11 171 24 181 17 124 9 66 5 ll total fish 89 1604 76 1537 378 7096 132 3168 52 1157 39 309 15 518 6 178 a ~ b Number of individuals. Total weight in grams. Includes fragments. Primarily pinfish.

TABLE 8-] (continued) NUMBER AND BIOMASS OF SHELLFISHES ND FISHES COLLECTED DURING 24-HOUR IMPINGEMENT SURVEYS AT THE ST. LUCIE PLANT 1977

Dates 9-10 MAY 1 26-27 MAY Cate or No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. shrimp 9 14 12 9 4 6 70 127 29 32 30 43 9 15 12 22 blue crab 2 113 2 149 2 43 8 51 3 207 2 205 stone crab 1 5 2 34 spiny lobster 1 1 shark, ray herring anchovy catfish jack 4 2031 8 5230 8 5501 10 5216 15 10249 15 10159 12 7726 9 5651 mojarra grunt 4 3 2 2 1 1 1 1 2 croaker 1 35 blenny, gaby 1 1 1 1 1 1 2 4 2 5 2 3 cutlassfish 1 748 scorpionfish, searobin 4 6

flounder, sole 5 31 4 6 1 15 2 34 1 13 1 1 triggerfish,filefish puffer, trunkfish

other fish 7 12 1 3 4 11 1 1

total shellfish 11 127 15 163 6 49 78 178 29 32 33 78 12 222 14 227 total fish 14 2069 24 5252 12 5519 16 6037 20 10262 22 10176 15 7744 13 5656

Number of individuals. Total weight in grams. Includes fragments. Primarily pinfish.

TABLE B-1 (continued) NUHBER AND BIOMASS OF SHELLFISHES AND FISHES COLLECTED DURING 24-HOUR IMPINGEHENT SURVEYS AT THE ST. LUCIE PLANT 1977

ates 31 HAY-1 JUN 9-10 JUN 13-14 JUN 16-17 JUN 23-24 J 24-25 JUN Cate or No. Wt. No. Wt. No. Wt. No. Mt. No. Wt. No. Mt. No. Mt. No. Wt. shrimp 30 52 48 92 24 34 17 27 22 30 7 10 8 11 12 16 blue crab 1 29 1 2 1 25 2 466 2 140 1 1 stone crab 1 25 1 23 1 1 spiny lobster 3 7 2 4 1 2 1 3 shark, ray herring anchovy catfish jack 7 2458 11 5619 7 3606 4 3088 3 218 2 872 mojarra grunt 1 1 162 6397 9 246 croaker 2 82 blenny, goby 2 ll 1 3 13 37 3 3 cutlassfish scorpionfish, searobin flounder, sole 3 8 1 1 triggerfish, filefish 1 2 puffer, trunkfish other fish 2 4 1 5 3 841 1 1 total shellfish 31 81 52 101 27 63 20 518 25 172 7 10 10 35 14 20 total fish 15 2483 16 5631 10 3614 8 3930 5 222c 178 6518 14 1121

Number of individuals. Total weight in grams. Includes fragments. TABLE B-1 (continued) NUHBER AND BIONASS OF SHELLFISHES AND FISIIES COLLECTED DURING 24-HOUR INPINGENENT SURVEYS AT THE ST. LUCI PLANT JULY-DECENBER 1977

Dates 27-28 UN 30 UN- UL Cate or No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. shrimp 27 45 32 55 34 51 48 73 50 64 339 520 195 259 92 91

- - - - 1 21 blue crab 2 17 5 26 - - 1 77 12 2 stone crab 60 3 105 spiny lobster 2 13

shark 1 311 herring anchovy catfish jack 1 5 1618 1 426 c 6 mojarra 1 2 1 2 24 67 3 grunt 1 3 1 6 croaker 4 5 9 8 1 4 blenny, goby 1 10 7 47 1 1 4 63 cutlassfish scorpionfish, searobin flounder sole 1 5 triggerfish, filefish 2 puffer, trunkfish 4 other fish 6 1013 3 6 1 1 2 1 4 3 13 15 1 8 total shell fish 30 122 37 - 81 34 51 49 150 53 169 341 533 196 271 94 112 total fish 9 1024 9 1625 3 432 9 51 3 10 10 392 37 99 14 26

Number of individuals. Total weight in grams. Includes fragments. l

I TABLE B-1 (continued) NUMBER AND BIOIIASS OF SHELLFISHES AND FISHES COLLECTED DURING 24-HOUR IMPINGEMENT SURVEYS AT THE ST. LUCIE PLANT 1977

Dates Cate or No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Mt. No. Mt. No. Mt. Ho. !At.

shrimp 121 153 112 160 140 201 96 149 422 595 1057 1408 317 87 101 83 119 blue crab 12 182 12 100 2 17 3 25 4 37 34 362 17 104 25 266 stone crab 2 6 I 2 I 6 spiny lobster 2 18 1 2

shark

herring I 3 anchovy catfish jack I I CO mojarra 4 7 7 31 I I 23 38 2 5 8 I 4 grunt 2 8 118 892 29 50 230 523 3019 31 197 croaker 6 8 4 12 9 9 16 blenny, goby 2 7 1 4 3 34 20 cutlassfish 1 930

scorpionfish, searobin 1 9 2 4 h 2 3 3 3 2 27 flounder. sole 2 3 6 1 4 2 18 triggerfish, filefish I 2 1 2 puffer, trunkfish 2 I 4 4 other 12 4 160 3 5 14 132 4 8 5 24 .2

total shellfish 123 171 124 342 154 307 98 166 425 620 1062 1447 353 765 104 205 108 385 total fish 5 15 15 194 15 47 11 29 161 1111 18 54 66 318 537 3982 38 232

a b Number of individuals. Total weight in grams. Includes frag!ants. I I

I TABLE B-I (continued) NUHBER AUD BIOHASS OF Si)ELLFISIIES AHD FISIIES COLLECTED OURIHG 24-!)OUR IFPIIIGEHE)lT SURVEYS AT THE ST. LUCIE PLAIIT 1977

Dates Cate or Ho. Wt. I)o. Wt. t(o. Wt. !lo. Wt. 1!o. Wt. Ho. Wt. Ilo. Wt. tlo. Wt. fio. Wt.

shrimp 34 45 394 863 125 254 243 530 41 87 77 167 69 132 28 52 16 29 blue crab 4 31 138 952 28 332 14 43 7 156 5 38 5 44 - - 2 25 stone crab I I I I spiny lobster 15" I I ~ 30 I 3

shark I I] herring 2 17 anchovy I catfish I 9 9 13 16 jack I 4 I 2 I 7 mojarra I 10 I I ) 4 12 49 ll 75 65 322 12 66 I 4 grunt 5 13 1 I 318 2019 7520 44448 1262 18529 136 498 124 croaker 451 87 454 59 334 117 685 )24 702 3 16 12 40 34 833 I 2 I 2 3 20 blenny, goby I 3 I 541 5 52 85 896 2 14 2 .7 cutlassfish I 9 2 48 scorpionfish, searobin ) 12 I 5 fI oun der,so)e 10 2 7 I triggerfish, filofish 2 2 343 14 2 22 puffer, trunkfish I g 2 196 2 14 other fish 2 14 11 84 27 1053 14 55 7 42 9 131 7 37 c total shellfish 533 1830 154 587 257 573 49 273 83 208 74 176 28 52 19 55 total fish 7 c 4 105 I. I)umber of individua)s. Total weight in grams. Includes fragments. TABLE B-1 (continued) NUMBER AND BIOMASS OF SHELLFISHES AND FISHES COLLECTED DURING 24-HOUR IMPINGEHENT SURVEYS AT THE ST. LUCIE PLANT 1977

Dates b Cate or No. Wt. No. Wt. 9 . Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. shrimp 5 16 18 54 21 62 9 25 22 126 7 21 8 23 73 228 96 178 blue crab 2 24 1 15 3 50 8 113 12 150 1 16 8 100 9 221 stone crab 1 1 1 1 spiny lobster 1 32 1 1 1 1 1

shark herring 1 3 4 I 1 anchovy 21 25 1 2 7 11 17 45 3 4 26 34 58 107 catfish 1 343 jack I I I 17 3 3 2 1 6 55 mojarra 2 6 1 1 24 1'12 10 48 1 7 3 14 grunt 8 5 120 2 33 1 6 12 86 3 9 1 6 5 19 5 26 croaker 2 4 22 44

blenny, goby 1 16 I 6 1 4 1 7 2 32 cutlassfish scorpionfish, searobin 1 17 2 6c 62 272 flounder, sole 2 19 2 8 triggerfish, filefish 1 1 2 2 2 1 2 puffer, trunkfish 26 3 25 I- 1 11 other fish 10 4 375 1 1 18 19 10 11 48 = 41 1867

total shellfish 7 40 21 102 25 113 9 25 30 239 21 174 9 39 82 329 107 401 total fish 8 66 34 551 8 5g 20 12 52 '231 25 80 16 68 55 162 204 2771

a ~ . b tiumber of individuals. Total weight in grams. Includes fragments. TABLE B-1 (continued) NUMBER AND BIOMASS OF SHELLFISHES ANO FISHES COLLECTED DURING 24-HOUR IMPINGEMENT SURVEYS AT THE ST. LUCIE PLANT 1977

Dates 10-11 NOV 14-15 NOV 17-18 NOV 21-2 N a b Cate or No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. No. Wt. shrimp 25 62 40 75 32 103 28 56 31 64 5 12 10 17 7 12 30 79

blue crab 2 36 7 138 7 152 6 99 3 51 1 59 5 143 stone crab 2 8 2 32 2 35 1 29 1 1 2 33

spiny lobster 1 1

shark

herring 1 7

anchovy 4 8 2 3 1 1 1 4 catfish I 103

jack 4 51 7 8 mojarra 9 55 1 7 3 8 2 5 7 22 2 3 1 3 3 grunt 10 57 18 94 13 87 2 10 7 40 2 14 2 17 croaker 2 11 3 43 4 12 1 6 1 ll 1 9 blenny, goby 1 1 1 3 1 38

cutlassfish 1 1

scorpionfish, searobin 8 284 3 7 1 2 3 13 1 2 1 4 fiounder,sole 1 10 1 12

triggerfish, filefish 1 2 1 5 4 15 1 3

puffer, trunkfish 4 283 2 176 1 23 other fish 2 22 2 8 5 .29 1 73 4 112 1 3 2

total shellfish 30 107 47 213 39 255 34 155 36 147 8 106 11 46 8 13 37 255 total fish 41 825 36 402 40 165 10 58 20 162 6 29 7 133 2 6 8 74 a ~ b Number of individuals. Total weight in grams. Includes fragments. l TABLE B-1 (continued) NUMBER AND BIOMASS OF SHELLFISHES AND FISHES COLLECTED DURING 24-HOUR IMPINGEMENT SURVEYS AT THE ST. LUCIE PLANT 1977

Dates Total Percentage Total Percentage Cate or Ho. Wt. No. Wt. No. Wt. No. Wt. Ho. Wt. No. Wt. Number Co os ition We i ht Co os ition shrimp 100 194 50 142 31 103 11 62 11 33 9 25 6390 88. 7 12955 42. 1 blue crab 42 407 14 382 6 82 4 249 8 101 8 16 727 10.1 16913 54.9 stone crab 1 23 2 5 2 14 ------59 0.8 710 2.3 spiny lobster 1 2 1 86 26 0.4 227 0.7

shark 8 0.1 2348 0.9 herring 10 618 2.9 2644 1.0 anchovy 66 97 3 5 2 4 4 7 10 6049 28.0 8319 3.1 catfish 274 26 0.1 — 1663 0.6 jack 1019 4.7 108062 40.9 mojarra 4 14 1 1 2 2 12 1435 6.6 9876 3. 7

grunt 12 51 1 1 5 1 6 8 45 12 10855 50.3 82150 31. 1 croaker 2 2 20 327 1.5 9449 3.6

blenny, goby 1 2 1 1 2 217 1.0 1754 0.7 cutlassfish 11 9 0.1 2573 1.0 scorpionfish, searobin 8 434 4 15 1 8 6 18 157 0. 7 2507 0.8 flounder, sole 1 1 1 21 1 1 2 26 182 0.8 2001 0.7

triggerfish, 1 filefish 10 71 0.3 9449 3.6 puffer, trunkfish 1 2 1 12 87 0.4 5236 2.0

other fish 4 25 1 2 449 1 4 6 544 2.5 16423 6.3

total shellfish 144 626 66 529 39 199 15 311 1 9 134 18 127 72p2 1pp p 308p5 1pp p total fish 98 636 14 124 7 738 12 50 18 106 29 122 21604 100.0 264454 IPP.P a Number of individuals. Total weight in grams. l TABLE B-2

TOTAL NUMBER OF INDIVIDUALS, WEIGHT IN GRAMS AND PERCENTAGE COMPOSITION BY TAXON OF SHELLFISHES AND FISHES COLLECTED DURING IMPINGEMENT SAMPLING ST. LUCIE PLANT 1976 - 1977

~ 1976 1977 No. of X by Weight X by No. of 5 by Weight X by Taxon individuals numbers wei ht individuals numbers wei ht shrimp 2525 78.1 8499 23.9 6390 88. 7 12955 42.1 blue crab 690 21.4 26821 75.3 727 10.1 16913 54.9 stone crab 13 0.4 265 0.7 59 0.8 710 2.3 spiny lobster 4 <0.1 17 0.1 . 26 0.4 227 0.7 herring 152 0.9 623 1.2 618 2.9 2644 1.0 anchovy 8776 54.4 12327 22.9 6049 28.0 8319 3.1 Jack 4962 30.8 6575 12.2 1019 4.7 108062 40.9 mojarra 365 2.3 2918 5.4 1435 6.6 9876 3.7 grunt 453 2.8 5743 10.7 10855 50.3 82150 31.1 croaker 309 1.9 2444 4.6 327 1.5 9449 3.6 cutlassfish 458 2.8 2423 4.5 9 <0.1 2573 1.0 flatfi she 112 0.7 1562 2.9 182 0.8 2001 0.7 other fish 542 3.4 19149 35.6 1110 5.1 39380 14.9

TOTAL SHELLFISH 3,232 100.0 35,602 100.0 7,202 100. 0 30,805 100.0 TOTAL FISH 16 129 100.0 53 764 100.0 21,604 100.0 264 454 100.0 a Total of 45 24-hour sampling periods. b Total of 97 24-hour sampling periods. c Flounder, sole, tonguefish. TABLE B-3

TOTAL NUMBER OF FISHES COLLECTED BY GILL NET AT INSHORE (CANAL) STATIONS ST. LUCIE PLANT 1977

Date and station 27-28 Jan 2 -23 Mar Taxon 13 14 15 16 13 14 15 16 13 14 15 16 13 14 15 16 13 14 15- shark, ray 1 10 15 1 1 jack snapper 1 4 mojarra grunt 2 5 porgy 3 1 1 1 2 5 2 croaker 2 2 4 3 1 spadefish 1 1 2 1 mullet other fish 5 1 3 1 1 1 1 1 1 1 2

TOTAL 12 ll 8 1 8 1 5 0 13 2 16 0 2 3 4 0 5 13 1 a Combination of two nets per station per 24-hour period. l TABLE B-3 (continued) TOTAL NUMBER OF FISHES COLLECTED BY GILL NET AT INSHORE (CANAL) STATIONS ST. LUCIE PLANT 1977

Date and station 23-24 Mar Taxon 13 14 15 13 15 16 13 15 16 13 15 16 13 15 16 13 15 16 shark, ray jack 2 2 snapper 1 mojarra grunt 1 1 porgy 1 1 croaker 1 spadefish 19 7 10 1 10 mullet other fish

TOTAL 2 0 0 23 11 0 10 2 0 3 0 0 0 5 0 2 16 0 a Combination of two nets per station per 24-hour period.

TABLE B-3 (continued) TOTAL NUMBER OF FISHES COLLECTED BY GILL NETa AT INSHORE (CANAL) STATIONS ST. LUCIE PLANT 1977

Date and station 9-10 Jun -13-14 Jul ~5'M ' ~2 Taxon 13 15 16 13 15 16 13 15 16 13 15 16 13 15 16 13 15 16 shark, ray 1 jack 2 6 snapper 1 1 mojarra grunt 4 1 porgy 1 croaker 1 spadefish 1 2 6 4 mullet 2 1 other fish 2 1

TOTAL 0 9 0 3 12 0 0 0 0 2 16 0 0 3 0 23 2 0 a Combination of two nets per station per 24-hour period. I TABLE B-3 (continued)

TOTAL NUMBER OF FISHES COLLECTED BY GILL NETa AT INSHORE {CANAL) STATIONS ST. LUCIE PLANT 1977

Date and station 2 -21 Se 17-18 Oct 18-19 Oct 7-8 Nov 8-9 Nov 7-8 Dec Taxon 13 15 16 13 15 16 13 15 16 13 15 16 13 15 16 13 15 16 shark, ray 1 1 jack 6 22 3 1 2 snapper 1 1 15 2 1 1 mojarra 1 grunt 4 6 4 2 1 3 porgy 3 2 2 6 5 6 croaker 1 2 2 1 spadefish 1 1 mullet 3 5 3 8 other fish 1 2 4 1 3

TOTAL 5 2 0 0 0 0 0 0 0 18 57 0 17 15 0 21 5 0

Combination of tv'ets per station per 24-hour period. I

I TABLE B-3 (continued) TOTAL NUMBER OF FISHES COLLECTED BY GILL NET AT INSHORE (CANAL) STATIONS ST. LUCIE PLANT 1977

Date and station 8-9 Dec. Total station Total by Percentage Taxon 13 15 16 13 14 15 16 taxon corn osition shark, ray 13 2 19 0 34 8.4 jack 1 19 1 36 0 56 13.9 snapper 1 17 6 26 0 49 12.2 mojarra 2 3 0 0 1 4 1.0 grunt 1 14 7 20 0 41 10.2 porgy 1 29 3 15 0 47 11.7 croaker 7 2 14 0 23 5.7 spadefish 43 5 36 0 84 21.0 mullet 2 1 15 1 12 0 28 7.0 other fish 1 16 3 17 0 36 8.9

TOTAL 7 3 0 176 30 195 1 402 100.0 a Combination of two nets per station per 24-hour period. b Sampled three months only. TABLE B-4

TOTAL NUMBER OF INDIVIDUALS AND PERCENTAGE COMPOSITION BY TAXON OF FISHES COLLECTED BY CANAL GILL NET AT INSHORE STATIONS ST. LUCIE PLANT 1976 - 1977

1976 1977 No. of No. of Taxon individuals corn osition individuals corn osition

shark, ray 2 0.4 34 8.4 jack 38 7.7 56 13.9 snapper 62 12.6 49 12. 2 mojarra 10 2.0 4 1.0 grunt 80 16.2 41 10.2 porgy 16 3.2 47 11.7 croaker 125 25.3 23 5.7 spadefish 2 0 ' 84 21.0 mullet 97 19. 6 28 7.0 other fish 62 12. 6 36 8.9

TOTAL FISH 494 100.0 402 100.0

a Total of 33 sampling periods. b Total of 24 sampling periods.

B-100 TABLE 8-5

TOTAL NUMBER OF FISHES COLLECTED BY GILL NET AT OFFSHORE STATIONS ST. LUCIE PLANT 1977

Date and station 7 an 4 F Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5

Spanish mackerel 8 5 1 1 1 15 6 bluefish 139 166 Atlantic bumper 37 13 blue runner 2 3 1 1 1 1 3 1 crevalle jack other fish 6 6 2 1 13 1 1 14 1 3 2 2 1 7

TOTAL FISH 153 177 3 1 0 14 1 4 1 0 1 0 2 54 0 0 2 4 29 7 3 3 4 8

Date and station 20 Ma 9 Jun 15 Jul 18 Au Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 '4 Spanish mackerel 1 bluefish Atlantic bumper blue runner 1 1 1 3 12 2 crevalle jack other fish 5 I 4 1 1 32

TOTAL FISH 4 2 2 0 0 1 4 0 0 5 1 1 7 13 3 0 0 2 0 3 0 0 32 3 a One 30-minute set per station per month.

TABLE B-5 (continued) TOTAL NUMBER OF FISHES COLLECTED BY GILL NET AT OFFSHORE STATIONS ST. LUCIE PLANT 1977

Date and station 20 Se 26 Oct Nov 2 0 c Dec Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5

Spanish mackerel 31 12 172 1 2 71 9 66 bluefish 1 9 2 2 10 Atlantic bumper 19 41 38 63 blue runner 2 2 3 1 7 4 3 crevalle jack 3 1 1 other fish 23 9 6 11 17 22 1

TOTAL FISH 2 2 0 0 0 1 74 74 222 1 15 163 29 4 4 0 0 1 0 11 66 0 0 0

Date and station Total b station Tota by 1J Taxon 0 1 2 3 4 5 taxon corn osi tion

Spanish mackerel 59 33 240 1 3 71 407 33. 3 bluefish 140 175 2 1 2 11 331 27.1 Atlantic bumper 32 78 38 0 0 63 211 17.2 blue runner 19 30 10 0 3 9 71 5.8 ' crevalle jack 0 3 0 0 1 5 0.4 other fish 55 32" 13 8 47 43 198 16.2

TOTAL FISH 305 351 304 10 55 198 1 223 100.0

One 30-minute set per station per month. Delayed due to inclement weather. 1

I TABLE B-6

TOTAL NUMBER OF INDIVIDUALS AND PERCENTAGE COMPOSITION BY TAXON OF FISHES COLLECTED BY GILL NET OFFSHORE ST. LUCIE PLANT 1976 - 1977

1976 1977 No. of / No. of / Taxon individuals corn osition snd~vsduals corn ositson

Spanish mackerel 179 10. 3 407 33.3 blue fish 91 5.2 331 27.1 Atlantic bumper 557 32. 2 211 17.2 blue runner 273 15. 7 71 5.8 crevalle jack 327 18.9 5 0.4 other fish 307 17.7 198 16.2

TOTAL FISH 1 734 100. 0 1 $ 223 100.0 a Total of 10 sampling periods. b Total of 12 sampling periods.

B-103 TABLE B-7

TOTAL NUMBER OF FISHES COLLECTED BY TRAWL (ONE 15-MINUTE TRAWL PER STATION PER MONTH) ST. LUCIE PLANT 1977

Date and station 6 Jan 22 Feb 16 ~2 1 1 5 0 1 2 3 4 5 Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 2 3 4 seatrout other croakers 3 1 1 6 1 3 7 1 1 flatfi sha 1 2 1 2 1 9 19 2 grunt 1 4 1 1 1 searobin, scorpionfish 3 5 2 1 1 3 1 3 2 4 sand perch 9 1 2 1 mojarra 2 cusk-eel 2 2 1 1 1 lizardfish 1 3 1 2 1 1 1 1 3 4 5 2 other fish 1 5 1 22 1 4 4 2 3 3

5 TOTAL FISH 3 8 8 2 911 1 23 0 211 0 0 5 015 0 23 0 1 4 2 0 412 20 913 8

a Fl ounder, sole, tonguefi sh. TABLE B- 7 (continued) TOTAL NUMBER OF FISHES COLLECTED BY TRA'WL (ONE 15-MINUTE TRAWL PER STATION PER MONTH) ST. LUCIE PLANT 1977

Date and station 20 Jun 20 Jul 24 Au 19 Se 20 Oct Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 seatrout other croakers 1 1 flatfi sha 2 9 8 10 3 5 4 25 10 2 4 7 3 1 1 1 4 5 1 4 1 1 4 3 1 grunt 1 11 69 5 30 14 20 2 8 searobin, scorpionfish 4 6 4 2 3 1 2 1 1 7 1 2 1 4 3 2 7 1 1 3 7 sand perch 1 19 11 11 12 415 1 3 2 1 2 1 12 3 20 5 mojarra 6 1 4 16 1 3 2 81 9 2 cusk-eel 1 3 1 1 4 1 1 1 1 1 lizardfish 1 1 2 1 1 3 3 4 3 1 2 1 1 other fish 6 4 2 5 1 3 5 7 6 9 210 4 2 43 6 1 1 212 8 4 7

TOTAL FISH 7 10 37 20 35 18 51 89 52 12 8 12 8 22 20 9 6 8 121 23 24 13 12 66 0 9 7 8 7 23 a Flounder, sole, tonguefish. r TABLE B-7 (continued) TOTAL NUMBER OF FISHES COLLECTED BY TRAWL (ONE 15-MINUTE TRAWL PER STATION PER MONTH) ST. LUCIE PLANT 1977

Date and station 9 Nov 14 Dec Total b station Taxon 0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5 seatrout 16 536 54 16 536 0 0 0 54 other croakers 9 232 3 15 232 0 0 1 2 flatfisha 2 ll 2 7 2 2 2 1 7 3 6 18 24 54 61 24 39 grunt 1 1 6 2 2 1 46 96 0 0 2 34 searobin, scorpionfish 17 2 29 3 8 5 3 7. 9 29 28 22 23 59 sand perch 1 4 14 14 48 2 17 46 mojarra 1 1 10 106 16 0 0 5 12 cusk-eel 2 13 1 1 1 1 5 20 5 9 3 5 lizardfish 1 2 6 1 1 2 2 9 22 7 3 other fish 3 12 1 3 44 3 4 3 3 19 80 31 11 26 85

TOTAL FISH 34 824 4 12 5 150 13 15 10 19 7 19 250 1049 175 127 108 339 a Flounder, sole, tonguefish.

TABLE B-7 (continued) TOTAL NUMBER OF FISHES COLLECTED BY TRAWL (ONE 15-MINUTE TRAWL PER STATION PER MONTH) ST. LUCIE PLANT 1977

Taxon Total b taxon Percenta e corn osition seatrout 606 29.6 other croakers 250 12.2 flatfish 220 10.7 grunt 178 8.7 searobin, scorpionfish 170 8.3 sand perch 141 6.9 mojarra 139 6.8 cusk-eel 47 2.3 lizardfish 45 2.2 other fish 252 12.3

TOTAL FISH 2 048 100.0 a Flounder, sole, tonguef ish. TABLE B-8

TOTAL NUMBER OF INDIVIDUALS AND PERCENTAGE COMPOSITION BY TAXON OF FISHES COLLECTED BY TRAWL ST. LUCIE PLANT 1976-1977

1976 1977 No. of No. of Taxon individuals corn osition individuals corn osition seatrout 0 0.0 606 29.6 other croakers 13 2.0 250 12.2 flatfi she 129 19.6 220 10.7 grunt 61 9.3 178 8.7 searobin, scorpionfish 129 19. 6 170 8.3 sand perch 86 13.1 141 6.9 mojarra 26 4.0 139 6.8 cusk-eel 72 11.0 47 2.3 lizardfish 9 1.4 45 2.2 other fish 131 20.0 252 12.3

TOTAL FISH 656 100.0 2,048 100.0 a Total of 10 sampling periods. ~ Total of 12 sampling periods. Flounder, sole, tonguefish.

B-108 I

I TABLE B-9

TOTAL NUMBER OF SHELLFISH AND FISHES COLLECTED BY BEACH SEINE ST. LUCIE PLANT 1977

Date and station LJ' 29JI'—' 22 8 Taxon 6 7 8 6 7 8 ~6 7 8 6 7 8 6 7 8 ~6 7 8 6 7 8 s eckled crab 2 3 3 1 1 sand drum 1 6 5 1 1 1 3 60 4 1 12 7 kingfish 2 1 12 1 7 2 3 2 7 20 herring 1 2 11 35 38 mojarra 1 8 anchovy 2 12 Atlantic bumper Florida pompano 1 4 5 2 1 other jacks 1 1 other fish 15 3 1 1 2

TOTAL FISH 2 0 0 2 0 4 2 0 0 36 21 1 9 10 6 129 8 3 33 62 46 a Combination of three replicates per station per month. I TABLE B- 9 (continued) TOTAL NUMBER OF SHELLFISH AND FISHES COLLECTED BY BEACH SEINE ST. LUCIE PLANT 1977

Date and station ~26 Au ~23 Se 27 Oct 9 Nov 15 Oec Total/station Total by Taxon 6 7 8 6 7 8 6 7 8 6 7 8 6 7 8 6 7 8 taxon corn osition s eckled crab 3 1 1 1 3 1 2 2 10 9 6 25 100.0 sand drum 9 11 2 35 4 8 1 132 33 8 173 21.1 kingfish 29 12 14 10 27 7 2 2 1 4 2 3 105 55 12 172 21.0 herring 69 1 93 39 39 171 20.9 mojarra 9 31 24 1 17 31 33 81 9.9 anchovy 48 12 0 60 7.3 Atlantic bumper 12 32 44 0 0 44 5.4 Florida pompano 1 3 3 1 7 10 5 22 2.7 other jacks 2 2 23 2 2 5 2 1 1 5 31 6 42 5.1 other fish 1 15 3 3 3 1 1 1 25 9 20 54 6.6

TOTAL FISH 110 23 20 61 68 27 37 19 8 15 4 2 40 5 6 476 220 123 819 100.0

a Combination of three replicates per station per month. I

I I

I TABLE B-10

TOTAL NUMBER OF INDIVIDUALS AND PERCENTAGE COMPOSITION BY TAXON OF FISHES COLLECTED BY BEACH SEINE ST. LUCIE PLANT 1976-1977

1976 1977 No. of No. of Taxon individuals corn osition individuals corn osition sand drum 105 8.7 173 21.1 kingfish 108 8.9 172 21.0 spot 101 8.3 0 0.0 herring 510 42.1 171 20.9 mojarra 8 0.7 81 9.9 anchovy 159 13.1 60 7.3 Atlantic bumper 28 2.3 44 5.4 Florida 'pompano 43 3.6 22 2.7 other jacks 73 6.0 42 5.1 other fish 76 6.3 54 6.6

TOTAL FISH 1,211 100.0 819 100.0 a Total of 10 sampling periods. b Total of 12 sampling periods. l TABLE B-11

ANALYSIS OF VARIANCE: GENERAL LINEAR MODELS PROCEDURE DIFFERENCES IN CAPTURE RATES OF PAIRED BONGO NETS ST. LUCIE PLANT, 1977

EGGS Source DF Sum of s uares Mean s uare

Model 6 1277.78002015 212.9633369

Error~ 291 64249.99914364 220.79037506

Corrected Total ~ 297 65527.77916379

Source DF T e I SS F Value PR>F

Station 1248.17174117 1.13 0. 3440 Re licate 29.60827898 0.13 0.7145

LARVAE Source DF Sum of s uares Mean s uare

Model 6 '.43440290 0.57240048

Error 290 474.81099787 1.63727930

Corrected Total 296 478.24540077

Source DF T e I SS F value PR > F

Station 5 3.43280641 0.42 0.8365 Re licate 1 0.00159650 0.00 0. 9751

* Significant at a = 0.10.

B-112 I I I I I

I I I

I I TABLE 8-12

EXAMPLES OF THE VARIABLES, CLASS VARIABLES AND MODELS USED WITH THE GENERAL LINEAR MODELS PROCEDURE ST. LUCIE PLANT 1977

VARIABLES

1 X) 2 X3 g, Xp Dens it Stati on Re licate Intercept

Yil A Yiy 8 Yi) A Yiy B

CLASS VARIABLES

Station Re licate 1 2 A B il 12 13 i4

1 0 1 0 1 0 0 1 0 1 1 0 0 1 0 1

MODELS For station and replicate effects: t

= ~ + Y ~ BpXp + Byx ~ + 82X. + B3X + B X. Z. 1 i> 12 13 g i4 1 For station effects:

= Y ~ BpXp + Byx ~ + B2X ~ + E. 1 1 1 12 1

where: B is the respective slope Z is the error term. 1 TABLE B-13

ANALYSIS OF VARIANCE: COMPARISON OF CAPTURE RATE AT STATIONS 0 THROUGH 5 ST. LUCIE PLANT 1977

EGGS Sour ce DF Sum of s uares Mean s uare

Model 5 1248.17174117 249.63434823

Error 292 64279,66742262 220.13564186

Corrected Total 297 65527.77916379

Source DF T e I SS F value PR>F

Station 5 1248.17174117 1.13 0.3422

LARVAE Source DF Sum of s uares Mean s uare

Model 3.43280641 0.68656128

Error 291 474.81259437 1.63165840

Corrected Total 296 478.24540077

Source DF T e I SS F value ~ PR > F

Station 3.43280641 0.42 . 0.8355

* Significant at a = 0.10.

B-114 I I

I I I

I I I TABLE B-14

ANALYSIS OF VARIANCE: - BY SEASON EGG DISTRIBUTION AT STATIONS 0 5 ST. LUCIE PLANT 1977

Season Source DF Sum of s uares Mean s uare

Winter Model 5 2450.23066326 490.04613265 Error 66 20805.87951359 315.24059869 Corrected total 71 23256.11017685

Source DF T e I SS F value PR > F

Station 5 2450.23066326 1.55 0.1843

Source DF Sum of s uares Mean s uare

Spririg Model 5 2596.51143285 519.30228657 Error 65 23831.11567317 366.63254882 Corrected total 70 26427.62710602

Source DF T e I SS F value PR > F

Station 5 2596.51 143285 1.42 0.2293

Season Source DF Sum of s uares Mean s uare

Summer Model 5 1823.34219367 364.66843873 Error . 54 9338.11900295 172.92812968 Corrected total 59 11161.46119662 I Source DF T e I SS F value PR > F

Station 5 1823.34219367 2.11* 0.0777

Season Source DF Sum of s uares Mean s uare

Fall Model 5 9.44608719 1.88921744

Error 88 126.95678021 ,. 1.44269068 Corrected total 93 136.40286740

Source DF T e I SS F Value PR > F Station 9.44608719 1.31 0.2666

* Significant at a = 0.10. TABLE B-15

DUNCAN'S MULTIPLE-RANGE TEST: SUMMER DISTRIBUTION OF EGGS AT STATIONS 0-5 ST. LUCIE PLANT 1977

MEANS WITH THE SAME LETTER ARE NOT SIGNIFICANTLY DIFFERENT ~

ALPHA LEVEL'-«F 05 DF-54 MS=0 ~ 336318

GROUPING MEAN STA

16 '20653 10

2 '04158 10

1 903364 10

C 1 ~ 350259 C C 1 '12331 10 C C 0 '61241 10 I

I TABLE B-16

CORRELATION COEFFICIENTS BETWEEN DENSITIES OF EGGS AND LARVAE AND FOUR PHYSICAL PARAMETERS ST. LUCIE PLANT 1977

EGGS LARVAE 00 TURS TEMP SALINITY,

EGGS 1 00000 «0 ~ 04155 0 '8020 0 ~ 11094* 0 '4271 0 ~ 01413 0 ~ 0000 0 ~ 4757 0.0033 O.O558 0.0001 O.8093

298 , 297 264 298 286 294

LARVAE 1 ~ 00000 -0 ~ 21176* 0o13605* 0 '7265 -O.O49O9 0 ~ 0000 0 ~ 0005 0,0190 0 '214 0 ~ 4024 ?97 264 297 ?85 293

DO i.oOOOO 0 14501* 0 '7923 0 04255 0 ~ 0000 0 ~ 0184 0 ~ 0001 0 '946 264 264 252 260

TURB 1OQOOOO 0 '0870* Oi10261 0 ~ 0000 0 ~ 0004 0 ~ 0790 298 286 294

TEMP 1 00000 0 ~ 11628 0 ~ 0000 0 '511 286 282

SALINITY 1 ~ 00000 0 ~ nnnn ?94

*Significant at u = 0.05.

TABLE B-17

ANALYSIS OF VARIANCE: LARVAL DISTRIBUTION AT STATIONS 0 - 5 BY SEASON ST. LUCIE PLANT 1977

Season Source DF Sum of s uares Mean s uare

Winter Model 5 31.78464144 6.35692829 Error 66 214.78128866 3.25426195 Corrected total 71 246.56593010

Source DF T e I SS F value PR > F

Station 5 31.78464144 1.95* 0.0964

S Source DF Sum of s uares Mean s uare

Spring Model 5 1.18766380 0.23753276 Error 64 37.97546783 0.59336668 Corrected total 69 39.16313164

Source DF T e I SS F value PR> F

Station 5 1.18766380 0.40 0.8479

Season Source DF Sum of s uares Mean s uare

Summer Model 5 18.21219054 3.64243811 Error 54 113.00258667 2.09264049 Corrected total 59 131.21477721 I Source DF T e I SS F value PR> F

Station 5 18. 21219054 1. 74 0. 1401

Season Source DF Sum of s uares Mean s uare

Fall Model 5 2.08539346 0.41707869 Error 88 17.99035855 0.20443589 Corrected total 93 20.07575201

Source DF T e I SS F value PR> F

Station 5 2.08539346 2.04* 0.0799

* Significant at a = 0.10. I I I

I I

I I I I I TABLE B-18

DUNCAN ' MULTIPLE-RANGE TEST: HINTER AND FALL DISTRIBUTION OF LARVAE AT STATIONS 0-5 ST. LUCIE PLANT 1977

WINTER 1976-1977 MEANS WITH'HE SAME LETTER ARE NOT SIGNIFICANTLY DIFFERENT ~

ALPHA LEVEL>~ 05 DF=66 MS=3 ~ 25426

GROUPING MEAN STA

2 '33758 12

1 '21229 12

0 '40972 12

0 '78467 12

0 '06096 12

0 '68346

FALL 1977 ALPHA LEVELS.05. OF=88 MSm4 ~ OE 04

GROUPING MEAN STA

0 '20724 16

0 '14102 15"

0 '13313 16

0 '93173 15

0 0 '987'56 16

n. 0 '96680 16 TABLE B-19

PERCENTAGE COMPOSITION OF THE MAJOR CATEGORIES OF FISH LARVAE EY STATION ST ~ LUCIE PLANT HINTER (DECEMBER 1976-FEBUARY 1977) $$ $$ $ $ $ $ $$ $ $ $ $ $ $ $ $ ¹$ ¹$ $$$$$$ $$ $ $$$$ $ $$$ $$$$$$$ $$$$$$$ $$$$$$$$$$$ STATION $$ $$ $ ¹$ $ $ ¹$ $$ $ $ $$$ $ $$ $$$ $$ $$$$ $$$$$$ $ $ $ $ $$$$$ $ CATEGORY 0 1 2 3 4 5 11 12 ¹$ ¹$ $ $ $ $ ¹$ ¹¹$ ¹¹¹¹¹¹$ ¹¹$ ¹¹$ $ ¹$ $$ $ ¹$$ $ $ $ $$$$$ $ $ $$ $ $$$ $$$ $$$$$ $$$$ $ GERR EIOAE 1 ~ 3 0 ~ 3 5o'4 6o4 0 9 2 ~ 2 7 7 5 3 SC IAENICAE 1 ~ I C ~ 7 9 ~ 1 22 ~ 7 0o6 2 ~ 7 19 ~ 2 5 ~ 3 BLENIIDAE Oo8 Oo6 5 ~ 5 6 ~ 2 lo4 1 ~ 0 26o9 47 ~ 4 TETRAODONTICAE 0 ' OoQ 0 ' 0 ' Oo0 0 ' 0 ' 0 ' CLUFEIFORMES 95 ~ 0 96 ~ 2 70 3 49o4 93 ~ 6 89 ~ 8 23 ~ 1 26o 3 CARANG IDAE 0 ~ 0 0 ~ C Oo9 0 ~ 8 Oo2 0 ~ 2 0 ~ 0 0o0 GOBIIDAE Oo4 0 ' 0 ' 0 ' 0 ' 1 2 7 ' 5 ' BOTHIDAE 0 ~ 1 0 ~ 2 Oo3 0 1 0 1 0 ~ 4 0 0 Oo0 GOB I ESOCIDAE 0 ~ 0 0 ~ C 0 ~ 7 Oo0 Oo0 Ool 0 ~ 0 Oo0 OPH IDI IDAE Oo2 0 ~ 1 2 ~ 1 5 6 0 9 0 ~ 9 0 ~ 0 0 ~ 0 SERRANI DAE 0 ~ C 0 ~ 0 Oo4 0 ~ 1 0 ~ 0 0 ~ 0 0 ~ 0 0 0 SCQRPAENIDAE 0 ~ 0 0 ~ 0 0 ~ 0 0 4 Oo0 0 ~ 0 0 ~ 0 0 ~ 0 ATHER INI DAE ALL CTHE R LARVAE 0 ~ 8 1 5 4 ~ 4 7 ~ 2 1 6 1 2 15 4 1.0 ~ 5 4$ $ $ $ $ $$ $$$ $$$ $ $ $$ $$ ¹$ $$ $ $ $ ¹'$$ $ $$ $$$ $ $$ $$ $$ $ $$$$ $ $$ $$¹$ $$$$$$$$ $ K

I TABLE B-20

PERCENTAGE COMPOSITICN CF THE MAJOR CATEGORIES OF FISH LARVAE BY STATION ST LUC IE PLANT SPRING I MARCH 1977-MAY 1977)

$ $$$ $¹¹¹$ ¹¹¹¹$ $$ $$¹¹$ $ $ $ ¹$ $ $ $ ¹$ $$ $¹$ $ $¹$¹¹¹¹$ ¹¹¹¹¹¹¹¹¹$ ¹¹¹¹$ ¹¹¹¹ STATION

CATEGORY 0 1 2 3 4 5 11 12 $ ¹¹$ $ $ ¹¹¹¹$ $ $ $ ¹$ $ $ $ $ $ $ ¹$ $ $ $ $ $ ¹$ $ $ ¹$ $ $ $ $ ¹¹¹¹¹$ ¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹$ ¹ C ERR EI CAE 8 ~ 8 20e6 12o4 8 ~ 7 10 ~ 5 24 ~ 7 Oe0 Oe0 SCI AEN IOAE 0 ~ 0 0 ~ 0 3 ~ 4 1 1 2 ~ 0 0 ~ 0 0 ~ 0 0 ~ 0 BLENIIOAE 2 ~ 2 1 ~ 9 1 ~ 5 7 ~ 5 14e7 34el Oo0 0 ~ 0 TETRAOOONT ICAE 5 ~ 5 2 ~ 9 7 ~ 2 6 ~ 3 5o 9 le 0 0 ~ 0 0 ~ 0 CLUPEIFORMES 40o3 59 ~ 4 37 ~ 1 57 ~ 2 22 ~ 0 24 ~ 7 94 ~ 6 100. CARANG IDAE 5 ' 1 ~ 4 0 ' F 7 2e4 0 ' 5e4 0 ' GOBIICAE Oe0 0 AC 1 ~ 8 0 ' 1 ~ 5 2 ' 0 ~ 0 0 ~ 0 SOT HIOAE 0 ~ 8 0 ~ 0 0 ~ 0 0 ~ 0 2 ~ 2 2 ~ 0 0 ~ 0 0 ~ 0 OPH IOI IOAE 7 5 0 C 1 8 0 7 2 4 0 0 0 0 0 0 SERRANI DAE 1 3 2 ~ 5 3 ~ 1 3 ~ 7 2 1 2 ~ 6 0 0 Oo0 SCQRPAEN IOAE 2e7 0 ~ C 14e7 le4 Oe0 0 ~ 0 Oe0 0 ~ 0 ATHERINIOAE 1 ~ 3 0 ~ C 0 ~ 0 0 ~ 0 0 ~ 0 0 ~ 0 Oe0 Oo0 ALL CTHER LARVAE 24 ~ 1 lle3 17 ~ 0 ll~ 8 34 ~ 5 8 ~ 5 0 ~ 0 Oe0 $ ¹¹¹$ ¹¹¹¹¹¹¹¹¹¹$ $¹¹¹$ $ $ $$ $$$¹¹¹¹$ ¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹$ ¹¹$ ¹ TABLE B-21

PERCENTAGE COMPOSITION CF THE MAJOR CATEGORIES OF FISH LARVAE EY STAT ICY ST ~ LUC IE PLANT SUMMER ( JUNE 1977-AUGUST 1917) ¹¹¹$ $$ $ $ $¹¹¹¹¹$ $ ¹¹$ ¹¹$ $ $ ¹¹¹$ ¹¹$ $ ¹$ $ $$¹$¹¹$ ¹$ $$¹$¹¹¹$ ¹¹¹¹¹¹¹$ $ ¹¹4 STAT ION $ ¹$ ¹¹$ ¹¹$ $ ¹$ $ ¹$ ¹$ $ ¹¹$ $¹¹$ ¹$ ¹$¹$$$ $$$ $$$$ ¹$ $ $$ ¹ CAT EGORY 0 1 2 3 4 5 11 12 ¹¹$ ¹¹$¹¹¹$ $ $ $$ ¹$ $ ¹¹$ $ ¹¹¹¹$ $$¹¹¹¹¹$ $ $¹$ ¹¹¹¹$ ¹¹$ $$ ¹¹¹¹$ $$ ¹¹$ ¹$ $$$ $ GERREIOAE 2 ~ 8 0 ~ S 0 9 3 ~ 3 3 ~ 9 1 ~ 9 0 ~ 0 0 ~ 0 SC I AENIOAE 0 ~ 0 0 ~ 2 0 ~ 0 . 1 1 2 1 3 ~ 3 0 ~ 0 Oo0 BLENIIOAE 1 4 0 ~ 5 0 ~ 9 1 ~ 0 0 ~ 5 0 ~ 8 0 ~ 0 0 ~ 0 TETRAOOONTICAE 2o3 1 ~ 5 Oo8 lo8 lo8 Oo5 0 ~ 0 0 ~ 0 CLUPEIFORMES 82e9 81 1 93e0 74 8 87 1 85 ~ 5 92 ~ 3 94 ~ 7 CARANGICAE OeG 0 ~ 0 0 ~ 1 0 ~ 8 Oo3 0 ~ 2 OeO OeO GOBI IDAE 3 ~ 1 4e4 1 ~ 8 5o4 1 ~ 8 2 ~ 2 0 ~ 0 5o3 BOTHIOAE Oo9 2 ~ 0 0 ~ 2 Oe4 Oe3 0 ~ 4 7 ~ 7 0 0 GCB IESOC IOAE 0 ~ 0 Oo0 Oo0 0'3 Oo0 0 ~ 3 0 ~ 0 0 ~ 0 OPHIOI I C AE 0 ~ 0 1 ~ 5 Oo4 0 ~ 4 0 ~ 0 0 ~ 3 0 ~ 0 OeO SERRANIOAE le7 leG I. 1 leO Oo 1 1 ~ 8 0 ~ 0 0 ~ 0 SCORPAQN IDAE 0 0 2 3 0 ' 0 6 0 2 0 2 0 0 0 0 ALL CTHER LARVAE 4 ~ 8 4e6 0 ~ 9 9 ~ I 1e9 2 ~ 7 0 ~ 0 Oe 0 $ $ ¹¹$ ¹$¹¹¹¹¹¹¹$ $ $ ¹$ $ $ $ ¹$ $ ¹$ ¹¹¹¹¹¹¹¹¹$ $ $ $¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹$ ¹¹¹$ ¹¹

W W W

TABLE B-22

PERCENTAGE CCMPCSITICK CF THE PAJCR CATEGORIES QF FISH LARVAE BY STATION- ST ~ LUC I E PLANT FALL ( SEPTEMBER 1977-NCVEMBER 1977) ¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹$ ¹¹¹4¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹>¹¹ ¹¹4¹4¹¹¹¹¹¹¹¹¹¹¹¹¹4¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹STATION CATEGORY¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹SS¹¹$0 1 ¹¹¹¹S¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹2 3 4 5 11 12 GERREI DAE 9121682 ~ 89 ~ 53 ~ 80 ~ 000 SCIAENIDAE 10 ~ 9 9a3 5a'9 3 ~ 6 4 ~ 7 6 ~ 7 0 ~ 0 0 ~ 0 GLEN I ICAE 2e20 ~ 2391 ~ 51 ~ 2140 ~ 000 TETRAOOONTICAE 2o8 1 ~ 7 5 ~ 8 0 ~ 3 8 ~ 4 4 ~ 3 0 ~ 0 0 ~ 0 CLUPEIFORMES 57 ~ 6 69 ~ 9 29 ~ 9 68 3 52 ~ 7 40 ~ 1 Oe0 Oo0 CARANG IDAE la9 1 0 6 ~ 4 5o7 3 ~ 2 10 ~ 5 Oo0 Oo0 GOB I IDAE 3 ~ 5 1 ~ 2 5a3 3 ~ 6 1 ~ 7 6 0 0 ~ 0 0 ~ 0 BOTH IDAE 2 ' 9 ' 5 ' 0 ' 1 4 2 ' 100 100 GOB I ESOC IDAE 0 ~ 0 0 ~ 0 0 ~ 0 0 ~ 0 0 ~ 0 0 ~ 0 = 0 0 OoQ QPHIDIIDAE 5a3 2a5 17e8 6a 1 10a9 BaO OaO OaO SERRANIDAE 0 ~ 0 0 ~ 4 0 ~ 0 0 ~ 6 0 ~ 0 4 1 0 ~ 0 Oo0 SCORP AEN IDAE le2 0 ' 3al OaO Oa0 6o4 0 ' OoO ALL¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹4¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹OTHER LARVAE 2 ~ 8 1 ~ 5 9 4 6 ~ 6 6 ~ 3 6 ~ 1 0 0 0 0 TABLE B-23

OCCURRENCE OF GRAVID FISH IN THE VICINITY OF THE ST. LUCIE PLANT JANUARY 1976-DECEMBER 1977

S ecies- Jan Feb Mar A r Ma Jun Jul Au Se Oct Nov Dec menhaden clupei d cusk eel striped mullet white mullet lizardfish black margate pinfish pigfish sea bream sheepshead silver porgy spot banded croaker Atlantic croaker i i silver seatrout highhat reef croaker gulf kingfish searobins guaguanche striped mojarra gafftopsail catfish oyster blenny seaweed blenny hairy blenny Atlantic cutlassfish bluefish scad blue runner i i Atlantic bumper i midshipman sand perch rock sea bass lane snapper i frigate mackerel Spanish mackerel i spadefish spotted whiff dusky flounder

B-124 Plate 1. Unidentified larva,4.7 mm total length.

Plate 2. Unidentified larva, 6.1 mm total length. I I

I I

I Plate 3. Larval scombrid, 7.7 mm total length.

Plate 4. Antenna codlet, 9.0 mm total length. 1

A t I 'p

I l

\ =

) 4 ~ 4 t I I I Plate 5. Larval scorpionfish (scanning electron micrograph).

Plate 6. Post-larval barracuda with chaetognath in jaws. 1

U I .,

t I

*'p . . 1

I Plate 7. Feather blenny, developmental series. 4, l

I C. MACRO INVERTEBRATES

INTRODUCTION

Marine macroinvertebrates spend at least part of their lives on or within bottom sediments, pilings, rocks, or other substrates. Because their- mobility is limited, these animals cannot avoid stressful conditions and therefore serve as useful indicators of environmental perturbations. Monitoring of marine macroinvertebrate communities in the St. Lucie Plant area provides information concerning the effects of power plant operation on the offshore ecosystem.

Three types of benthic communities are found in association with distinct sediment types in the vicinity of the St. Lucie Plant. The first of these is the depauperate, low-density macroinvertebrate fauna found on the beach terrace. This zone, which extends from shore to about 8 meters deep, has a fine sandy bottom. The 1977

Stations 0 and 1 are located on the beach terrace. A more diverse assemblage is found farther offshore where sediments of shell material provide habitats for macroinvertebrates, including a fouling community. Stations 2, 4, and 5 are located in this offshore trough.

The third type of benthic community is found farther offshore on

Pierce Shoal, where Station 3 is located. The medium sand substrate of the offshore bar supports another characteristic macroinvertebrate assemblage.

C-1 I I I

I This report presents grab and trawl data collected from March

1976 through December 1977. Analyses of macroinvertebrate community

N abundance and diversity are discussed in relation to environmental

parameters and community trophic levels. The data are also compared with the invertebrate larvae abundance and distribution results from the zooplankton sampling program. Comparisons of the present study with published baseline information ( 1971-1973) will be used to discern long-term trends.

MATERIALS AND METHODS

Two sampling programs designed to study macroinvertebrates in the oceanic environments near the St. Lucie Plant were conducted in 1976 and 1977. Except for minor changes, study methodologies re- l mained the same during both years (see Table C-1). Bottom sediments and fauna living in and upon the sediments were collected with a

Shipek benthic grab sampler. Trawl samples provided data on those macroinvertebrates living on or near bottom.'ater temperature, salinity, dissolved oxygen conceptration, and turbidity data were collected at surface, mid-depth, an4 bottom of each station during both trawl and grab sampling.

Shi ek Grab Sam les quarterly grab sampling for the smaller benthic i nfauna (organisms living within the substratum) and epifauna (organisms living on top of the substratum) began i n March 1976 at six offshore locations

C-2 l

I (Figure C-l, Table C-2). Stations 1 through 5, located near the plant discharge structure, corresponded to locations sampled during preliminary studies conducted from 1971 to 1974 by the Florida Oepart- ment of Natural Resources (Gallagher and Kollinger, 1977). An additional station (Station 0), located 4.3 kilopeters south of the plant discharge, served as a control for the 1976-1977 studies (Table C-2).

The Shipek grab sampler consists of two concentric half- cylinders. The inner half-cylinder (20 x 20 x 10 cm) rotates through

180's the sampling scoop (Figure C-g). When the sampler is lowered to the bottom with winch and line, power'ful helical springs close the two half-cylinders so that the 'sample cannot escape.

Four replicate samples were taken quarter ly at each offshore station. Each sample was preserved in a 10/ buffered formalin-seawater solution and stained with rose bengal. Three of the four replicates taken at each station were washed through a No. 25 sieve to remove fine sediment and particulate matter. This screen size and procedure were used to conform with previous offshore benthic monitoring programs conducted by the Florida DNR (Gallagher and Kollinger, 1977).

All material retained on the sieve was hand-sorted under low magnification in the laboratory, where the stained organisms were identified to the lowest practical taxon.

C-3 I I I

l The fourth replicate was similarly sorted, but the organisms (exclusive of molluscan shells) were dried at 105'C for four hours, then weighed to provide an estimate of'ommunity biomass per uni t area. Because the character of the substratum is a major determinant of benthic macroinvertebrate distribution, the substratum material of the fourth replicate was dried, disaggregated, and placed in a nest of nine sieves (mesh widths of 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, and 0.063 mm). The nest was shaken for 15 minutes on a Tyler Ro-Tap sieve shaker. The substratum was then analyzed according to the method of Folk (1966) for mean particle diameter, sorting coefficient

(standard deviation of mean particle size), and particle size distribution.

To assess the adequacy of three replicates to sample the species present in the study area, additional samples to determine species saturation were taken at two stations during the March 1977 sampling.

Trawl Studies

The trawl sampling program for invertebrates was conducted in conjunction with the fish sampling program (see Section B, Fish and

Shellfish). Trawls were made at night to reduce net avoidance. One

15-minute tow was made with a 4.9-m semi-balloon otter trawl at each offshore station per month. The samples were preserved in 10/ buffered formalin-seawater solution, labeled, and transported to the laboratory for sorting and identification to the lowest practicable taxon. C-4 II

I RESULTS AND DISCUSSION Substrata

Many environmental parameters are known to affect the structure and distribution of marine benthic communities. Among the more important is substratum type. Sharp distinctions occur between fauna associated with hard and soft substrata. Hard substrata are usually represented by rock outcroppings and coral reefs; to a lesser extent they are also represented by large fragments of mollusc shell. These hard substrata generally support a wide variety of cryptic, boring and epifaunal species. Soft substrata, such as the biogenically derived sediment reported by Hathaway (1971) to be widespread on the nearshore continental shelf adjacent to Hutchinson Island, may be expected to support a somewhat lower infaunal biomass and species diversi ty (Abele, 1974).

Many researchers have correlated various sediment parameters such as grain size and material composition with the species distribution and diversity of benthic macroinvertebrates (Sanders, 1968;

Lie, 1968; Lie and Kelley, 1970). Most of this work has focused on benthic communities associated with sand and mud substrata, and little effort has been expended studying the benthic macroinvertebrate communi ty of a shell-hash habitat. Substratum analysis was needed to provide data for describing this little-studied benthic community.

Substratum samples were analyzed for mean particle size, particle size class distribution, and sorting coefficient. The sorting

C-5 coefficient, or standard deviation of the mean particle size, was used to describe the degree of sorting or homogeneity of sample particle size as follows:

Sorting Coefficient

0.35 5 very well sorted 0.35-0.50 6 well sorted 0.50-0.71 6 moderately well sorted 0.71-1.0 0 moderately sorted 1.0 -2.0 6 poorly sorted 2.0 -4.0 0 very poorly sorted over 4.0 5 extremely poorly sorted

As discussed in the baseline study (Gallagher, 1977) and the

1976 annual report on the present sampling program (ABI, 1977), the I study area'can be divided into three zones based on sediment characteristics (see Appendix Table L-1): 1. the beach terrace (Station 1) 2. the offshore trough (Stations 2, 4, and 5) 3. the offshore bar-Pierce Shoal (Station 3).

Station 0 was located in a trough-type substratum in 1976 but was moved inshore to a beach terrace-type substratum in 1977.

In 1977, beach terrace sediments were found to be fine to very fine, moderately well-sorted, gray, non-biogenic (quartz) sand. This sediment type was found at Stations 0 and 1 on the seaward edge. of the terrace. Offshore trough sediments consisted of very poorly to extremely poorly sorted, very coarse particles, This sediment type is termed "shell hash" since it is composed almost entirely of broken

C-6 mollusc shells. Trough sediments characteristically exhibited large variations in mean. particle size and sorting coefficient. A significant quantity, 14 to 33K, of gravel-sized shell particles (>2.0 mm) was typical of trough sediments. Large shell particles imparted heterogeneity, with resultant good porosi ty, to trough sediments. The substratum at Pierce Shoal was a well-sorted, medium, calcareous sand.

The general homogeneity of the substratum at Station 3 probably results from storm-induced hydrological processes that selectively transport medium and fine particles to the shoal crest while removing the larger particles (Duane et al., 1972). This selective process resulted in a homogeneous substratum that, because of representative particles, probably retains good porosity.

Gallagher (1977) reported that mean grain sizes of all three substratum types exhibited temporal and spatial variation during the e baseline study of 1971-73. Station 4 sediments were least varied. Significant textural changes were rarely observed in the beach terrace (Station 1) or Pierce Shoal (Station 3) sediments. Due to the homogeneity of sediments at these stations, however, relatively small compositional changes produced statistically significant differences.

These textural changes were probably of insufficient magnitude to affect the distribution of the benthic fauna., Trough sediments exhibited the largest spatial variation, as i ndicated by large sorting coefficients and wide ranges in mean grain size. The substratum at

C-7 'P Station 5 had larger percentages of gravel and coarse shell particles than either Stations 2 or 4, al.though the differences were not statistically significant.

The Mann-Whitney U test (Elliott, 1971; Appendix Table L-2) was applied to mean grain size data from each station to determine P if significant textural changes had occurred during the present studies. Sediments at Station 1 were found to be significantly different (P=0.05) between 1976 and the baseline study. Coarser mean grain size during December 1976 resulted from a quantity of broken shell particles that, considering their blackened color, had been buried for some time and recently uncovered. Mean grain sizes for remaining samples in 1976 were only slightly coarser compared to all other Station 1 sediment data (Figure C-3). Textural changes in 1976 could have been the result of installation of the plant discharge pipeline. Observed changes might also be a result of high-energy sediment transport. Such an assessment would be difficult to make due to the highly dynamic physical nature of this ecosystem. With continued plant operation during 1977, the sediment at Station 1 returned to a distribution typical of that found in the baseline study.

A large, though not statistically significant, change in mean particle size was observed at Station 5 in 1976 compared to

C-8 l,

1 1971, 1973 and 1977. Differences in the gravel fraction, which averaged 18'A in 1976, 34K during the baseline study, and 33Ã in

1977, were responsible for the observed differences. As expected, large variation was also noted at Station 0 because this station was moved in 1977.

Evaluation of Sam le Ade uac for S ecies Accumulation

The number of replicate samples required to adequately describe the benthic community is predicated on the relative number of individuals and species inhabiting a given environment, the apportionment of individuals among the species, and the spatial distribution of the organisms present.

To determine the adequacy of three Shipek sample replicates, a short study was conducted to determine if additional bottom samples would produce significantly more species not previously encountered. Additional replicates were taken from Stations 1 and

5 during March 1977, and the data were graphed showing the number of species accumulated per replicate of increased sample effort (Figure C-4). These data produced irregular and erratic curves because of the chance ordering of haphazardly collected samples containing various numbers of taxa. These data were then compared with a theoretical population (generated by a statistical procedure developed by Gaufin et al., 1956; see Appendix Table L-2) that produces a smooth curve. From this curve, the proportion of species

C-9 h in N samples can be estimated. The point at which the Gaufin cumulative curve becomes asymptotic is the point at which additional sample replicates will probably not produce additional, species.

In relatively undisturbed environments, a few species are generally represented by large numbers of individuals while many species are represented by only a few (EPA, 1973). Longhurst (1959) suggested that in such a situation, the abundant species are usually adequately sampled well before the asymptote of the Gaufin cumulative curve is reached. Therefore, the benthic community may be satis- factorily described with fewer than the total number of samples needed to sample all species residing in the area.

Seven replicates were taken at Station 5, which typically yields a large number of species and individuals. Of the 203 species collected,- 154 were contained in the first three replicates.

The Gaufin cumulative curve predicted about 150 species as the average number of taxa expected from three replicates. These data suggest that, at shell-hash substrates similar to those at Station

5, three replicates are sufficient to sample about 75K of the taxa present. The relatively steep slope of the Gaufin cumulative curve indicated that substantially more than seven replicates would be needed before the curve would become asymptotic.

The slope of the Gaufin cumulative curve is positively correlated with the total number of taxa in all samples (Long- hurst, 1959). The presence of large numbers of taxa represented by single specimens would account for the relatively steep slope.

Hithin the seven replicates taken at Station 5, 251 of the taxa were represented by only one specimen each. This agrees closely

with the 26/ value obtained for the entire 1977 study.

Ten replicates were taken at Station 1 on the beach terrace where fewer numbers of individuals and taxa exist. Of the 82 taxa collected, 51 were encountered in the first three replicates.

However, the Gaufin cumulative curve indicated that on the average, only 39 of, the taxa would be expected in that number of samples.

This difference was due primarily to the sparse distribution of

species on the beach terrace. Forty-five percent of the taxa in 10

replicates were represented by one specimen. Again, this is closely

aligned with the 46K value obtained for the entire year (1977).

Thus, beyond three replicates, most previously uncollected taxa would probably be represented by few individuals.

In summary, three replicates were demonstrated to be adequate

in providing representative members of up to about 75% of the

species that theoretically could be present in a greatly increased

sample population.

Evaluation of Sam le Ade uac for Diversit Indices

Closely related to the number of individuals and taxa is the concept of faunal diversity. Diversity indices are an additional tool for measuring the quality of the environment and the effect of induced stress on the structure of a community of macroinvertebrates. Their use is based on the generally observed phenomenon that in undisturbed environments, there will be relatively few species with large numbers of individuals and large numbers of species represented by only a few individuals. Many forms of stress tend to reduce diversity by 'making the environment unsuitable for some species or by giving other species a competitive advantage.

Appendix Table L-2 outlines the Shannon-Weaver function (Lloyd et al., 1968) of diversity (d) and its utility as an indicator of environmental stress. Cumulative diversity values were plotted for replicate samples 'taken at Stations 1 and 5 (Figure C-5). It becomes apparent that sampling effort beyond three replicates has little effect on faunal diversity values, since the curves become asymptotic at an early stage of collection. Sanders (1968) reiterates the usefulness of the Shannon-Weaver information function, stating that it has the critical characteristics of being relatively independent of sample size.

C-12 I The equitability component (e) of diversity (I loyd and Ghelardi,

1964) describes the apportionment of individuals among the taxa present

and ranges from 0 to 1 (Appendix Table L-2). When the individuals in

a sample are evenly distributed among the taxa, equitability is high. Cumulative equitability (e) values were plotted for the replicate

samples taken at Stations 1 and 5 (Figure C-5). As this figure shows, equitability is reduced with increased replication. This situation is the result of continued acquisition of rare species coupled with large numbers of individuals of the dominant species. Thus, three replicates slightly overestimate the equitability component of diversity.

Seasonal Variation of Fauna in Henthic Grab Sam les

Trends in community parameters measured from benthic grabs showed considerable seasonal variation. Generally, variations in the density

of organisms were not accounted for by seasonal fluctuations in the population levels of any individual or group of taxa. Rather, the variable patterns exhibited were the result of cumulative fluctuations

in a large number of taxa. Seasonal trends, however, were sometimes inconsistent from year to year.

The observed trends showed little continuity during the study at most stations (Table C-3 and Figure C-6). Diversity values were generally high and well above the levels that the Environmental Protection

Agency suggests are indicative of healthy (non-polluted) environments

(EPA, 1973). Station 3 was the only location at which equitability l exhibited an obvious relationship with number of taxa and density.

In September when overall densities and numbers of taxa were highest, equitability was lowest. Most of the taxa were represented by relatively few individuals. When the dominant organisms decreased in abundance, the individuals were more evenly distributed among the taxa and equitability increased.

Only at Station 5 were biomass values significantly correlated with the density of organisms (Table C-4). Biomass is affected by both the absolute number of organisms present and by their relative sizes. The lack of correlation suggest that, in the study area, the average size of individuals within a taxon may be greater at less than maximum densities. However, biomass determinations were made from samples other than those used for species identification and enumer- ation. In patchy environments such as those encountered in the study area, large faunal variability between samples is often observed (Table C-3). The problem is further complicated when exceedingly large organisms, especially those which are infrequently collected, appear in the biomass sample.

Thus, seasonal trends of various communi ty parameters, with few exceptions, showed little relationship with one another. Because of the dynamic nature of the environment, these parameters also show little congruity from year to year.

Critical Variables: Tem erature and Substrate

Both temperature and substrate are known to be important in shaping benthic comnunity structure (Sanders, 1968; Boesch, 1972).

Substrate has previously been shown to be strongly related to faunal assemblages in the study area (ABI, 1977). However, no apparent seasonal fluctuations in substrates were detected through four years of sampling (including the baseline studies, previously discussed). Therefore, the observed seasonal fluctuation of the

community parameters measured from benthic grab samples cannot be attributed to changes in substrate. Temperature, however, obviously

varies through the seasons and affects benthic organisms in a number

of ways, including the establishment of geographical boundaries of distribution.

Spearman rank correlation coefficients (rs) were calculated for each station and for all stations combined to determine whether significant correlations existed between density and seasonal bottom

water temperatures (Table C-4). The mean density for all stations

combined displayed a trend similar to that observed for water temperature (Figure C-7) even though the two were not significantly correlated. Significant correlations between density and temperature were found only at Station 4. The lack of correlation at most stations suggests that recruitment of juvenile species is not re-

stricted to a particular season but occurs sporadically throughout I the year. Some organisms probably spawn continuously while others require various fixed thermal regimes. The resultant staggered recruitment may account for the continuous presence of small individuals of many taxa throughout the year. Day et al. (1971) noted a similar phenomenon for shelf benthos off North Carolina,'hich has environmental characteristics similar to those of the present study area.

Zooplankton studies (see Section E) indicate that polychaete and mollusc larvae showed little seasonal pattern in abundance (Figure C-8). Although meroplankton and the underlying benthos are certainly related, it is not obvious from the sample data presented.

One reason for the lack of similarity is that not all meroplankton will settle in the study area and those that do may have differential rates of survival. On an annual basis, it appears that the overall abundance of polychaete and mollusc larvae was higher during 1976, and this corresponds to higher densities of these groups in the adult population during that year.

Correlation coefficients between temperature and number of taxa collected at each station indicate that Stations 3 and 4 were the most seasonally predictable stations, both exhibi ting significant positive correlations (Table C-4). No other stations exhi bi ted this correlation, probably for reasons previously discussed.

C-16 I Figure C-9 depicts mean monthly bottom temperatures at Sta- tions 1 and 0. Thermal differences between the stations were not appreciable except during the suomer months, when Station 1 was about 1'C higher than Station 0. Even though the total number of taxa and density of organisms at Station 1 exhibited little variation between years (Table C-3), these parameters displayed opposite trends-, rising throughout the first year and declining the second (Figure C-6). It is doubtful that declining numbers of individuals and taxa were plant-related, since corresponding decreases were observed at Station 0 in a similar environment. Declining numbers of individuals and taxa during 1977 at these stations may reflect natural biological events occurring all along the beach terrace.

In su@nary, temperature as a critical variable showed little correlation with any community parameter at any station. This fact, coupled with the lack of appreciable thermal differences

) between stations, indicated little possibility of plant effect on seasonal benthic community parameters.

C-17 I

I Plant Effects on Benthic Fauna Collected b Grabs: 1976-1977

Because of the dynamic seasonal nature of community parameters observed in the vicinity of the St. Lucie Plant, it is difficult to segregate natural variations from plant-induced ones, if any.

Changes in the benthic community structure are not necessarily detrimental'. In fact, environments that are seasonally dynamic are often found to be quite stable on a long-term basis (Livingston, 1976). Nevertheless, the effects of environmental perturbation can still be observed by various types of benthic community analysis (Heck, 1976).

Benthic coranunity parameters analyzed were the number of taxa and number of individuals collected on a year-to-year basis. To test for significant differences in both of these parameters, each station was treated separately. Grab efficiency, which is defined here as depth of penetration, was also tested in a similar manner to delineate its effect on both numbers of taxa and numbers of

individuals collected. Since no one transformation would adequately "normalize" these data for use with parametric statistics, the nonparametric Mann-Whitney U test (Elliott, 1971; Appendix Table L-2) was applied.

Results from Shipek sampler penetration data (Table C-5) indi-

cates significant decreases in grab efficiency at Stations 0, 1 I and 5 from 1976 to 1977. The decrease at Station 0 was, of course, concomitant with its relocation onto fine, hardpacked sand. The observed decreases at Station 1 and 5 are believed to be due to a shift in grain size composition (Appendix Table L-1). This factor, as well as the presence of obstacles such as shells, might have caused the observed decreased efficiency at Station 5 (see Christie, 1975).

Except for Station 0, no decreases were observed either in number of taxa or number of individuals collected at any station between 1976 and 1977 (Table C-5). In fact, the number of taxa significantly increased at Stations 2 and.5. Both number of taxa and number of 'individuals significantly increased at Station 5 between 1976 and 1977 even though grab efficiency decreased. These two comnunity parameters remained stable between years at Stations

1, 3 and 4. Results of substrate analysis from Station 5 (Appendix Table L-1) indicate that the heterogeneity of the substrate is most likely responsible for the observed increases at that station from

1976 to 1977.

Mann-Whitney U tests were also applied to 1977 data for Station 1, at the plant discharge, and Station 0, which served effectively as a control in 1977. These results are thus of particular importance. No significant differences were observed between grab efficiency, number of individuals captured or number of taxa collected. This indicates no significant reductions of these benthic infaunal coranunity parameters during 1977 when the plant was essentially in full operation.

Com arison of Benthic Grab Diversit b Year

A graphic method was chosen to compare species diversity by station between 1976 and. 1977. This technique, known as the rarefaction method (Sanders, 1968), essentially interpolates the number of species distributed among any given number of individuals less than the total derived from the sample (see Appendix Table L-2).

In the rarefaction curves generated by this method, low diversity is indicated by fewer number of taxa per unit number of individuals

(i.e., high degree of dominance by a few taxa). Rarefaction measures for Stations 1 through 5 for each year of benthic macroinvertebrate data show little change at Stations 3 and 4 but slight increases in overall diversity at the remaining stations'(Figure

C-10). Station 1 in 1977 actually appears more diverse (less tendency toward dominance) than its counterpart (Station 0) in the same year.

Dominant Benthic Grab Ph la and Taxa

Changes in the percentage composition of the major groups of benthic macroinvertebrates are known to be indicative of environ- I

I mental perturbation (Rosenberg, 1976). If significant perturbation occurred in 1977 when the plant was in full operation, major shifts

in taxonomic groups would be expected to occur. In the shelly environment offshore from the St. Lucie Plant, annelids predominated

(50'A) over all other groups (Figure C-ll). Sipunculids, molluscs and arthropods generally comprised less than 17K by groups at these stations. Echinoderms and cephalochordates (lancelets) usually

comprised an even smaller percentage (<6/). The contribution to

the total community by each group at Stations 2, 4 and 5 remained relatively stable from 1976 to 1977.

At Station 3, in the medium sand environment, molluscs comprised the majority of individuals collected (>58%). Juvenile recruitment of the bivalve crassinezza auplznana was primarily responsible for this observation. Annelids and arthropods were the second and third most encountered groups, respectively, at that station. Percentage contribution by these groups exhibited very little change from 1976 to 1977. The most notable change at

Station 3 was the decrease in lancelet abundance in 1977. It

appears that thi s station is an area where mostly juveniles are collected (Futch and Dwinell, 1977), and a decrease in the settle-

ment of larvae that year was most likely responsible for decreased abundance. I

I I I In the fine sand at Station 1, annelids predominated (<40Ã), but not in as large a proportion as that found at the shelly stations. Arthropods and molluscs were the next most dominant, in order of decreasing percentages. Other minor phyla, primarily nemerteans, were the fourth 'major faunal component at Station l.

Nemerteans 'are found throughout the study area, but they may com- prise a larger percentage at Station 1 because other phyla are less abundant at Station 1 than at the other stations. The composition of dominant macroinvertebrate phyla at Station 1 remained essentially constant from 1976 through 1977.

The composition of benthic macroinvertebrate phyla in 1977 at

Station 0, which most closely resembles Station 1 in substrate composition and most reasonably serves as a control, was similar to that at Station 1 (1976 and 1977) except for an increased percentage of a'rthropod composition. A noticeable increase in abundance of cumaceans (Crustacea) during the first two quarters of sampling (March and June) was responsible for this disparity. Increased numbers of cumaceans were also found at Station 1 during this period, but not in the relative numbers collected at Station 0. Frankenburg (1971) found large increases in population density (3000/m') of the cumacean oxgurostylis smithi between January and June in the nearshore environment off the Georgia coast. The semi-planktonic, motile nature of this group could be responsible for the uneven distribution of

C-22 I I I

I these organisms along the beach terrace at a given point in time.

Generally, however, all stations sampled continuously in the same location through the 2-year period showed relatively constant percentage composition by the same phyla.

Replacement of dominant species (or taxa) in a benthic cormun- ity is known to be indicative of environmental stress; sequential change of dominating populations was recorded in an estuary following pollution abatement (Rosenberg, 1976). Dominance in this study was'etermined by McCloskey's (1970) index (Appendix Table L-2).

This method ranks each taxon by abundance and frequency of occurrence. The sum of rank "scores" for a species indicates its dominance value at a station. This method was used to determine the 10 top-ranked species for 1976 and 1977 at each station (Table C-6). A total of 56 taxa were classified as dominants. Thirty of these were annelid worms, 24 of which were polychaetes; molluscs and crustaceans were each represented by 10 taxa, and ech'inoderms by three taxa. Several of the taxa ranked as dominants may represent more than one species (e.g., sipunculida and nemertina) . As a result of Station 0's relocation, only one taxon remained in the top 10 between years there. Three taxa were in the top 10 both years at Station 1, but the gastropod, olivella floralia, represented the only single species. At Station 2, only four single species were ranked in the top 10 in both 1976 'and 1977. These were the polychaetes, Goniadides carolinea, Mediomastus californiensis,

Filogranula Sp. and the gaStrOpad, Crepidula fornicata. At StatiOn

4, the annelid WOrmS G. carolinea, Marionina Sp, and Filogranula Sp. were the only species ranked in the top 10 during 1976 and 1977.

At StatiOn 5, Filogranula Sp. WaS the Only SpeCieS tO remain a dominant through both years. Station 3 exhibited the most stability of the top-ranked dominants between 1976 and 1977 with a total of five single species. These included the molluscs crassinella dup- linana, Dentalium calamus and Glycymerus spectralis. The CruStaCean I species ranked in the top 10 fov both years were zurydice littoralis and Protohaustorius sp. A.

The number of dominant taxa shaved by Station 0 and Station 2 during 1977 was relatively high (five). These included the poly- Chaeta Mediomastus californiensis, and CruStaCeanS Cyclaspsis pustula, C. varians and synchelidium americanum. Taxa such as nemerteans and sipunculids present taxonomic difficulties and each group probably represented more than one species. However, they appeared as dominant in both 1976 and 1977 at almost every station and are obviously a functionally significant part of the informal community in the study area.

The apparent lack of continuity between dominant taxa collected in 1976 and 1977 i ndicates that, although the relative percentage t I

~HI l composition of major groups remained constant (Figure C-ll), the dominant components of these groups exhibited a'great deal of variation. Fifty percent of the dominant taxa, however, were shared at the discharge station (1) and that which serves as a control (0) during 1977.

Anal sis of Tro hic T es In order to provide characterization of the benthic community found at St.'ucie, the species collected there were segregated according to trophic level (location in the marine food chain).

The trophic types of the fauna collected in the Shipek sampling program were divided into seven categories: suspension feeders, deposit-suspension feeders, deposit feeders, herbivores, omnivores, carnivores, and others (see Appendix Tables L-3 and L-4). The food of deposit feeders can be plankton (alive or dead) deposited on the bottom, dissolved organic matter, plant detritus, and bacteria distributed on or within the sediments. Suspension feeders ingest plankton, dissolved organic aggregates, and bacteria from the water column (Levinton, 1972).

All habitats sampled exhibited a preponderance, of deposit feeders and suspension feeders (Figure C-12). Observed temporal fluctuations in suspension feeding population is attributed to fluctuations in food supply (Levinton, 1972). Carnivores were

C-25 I

I usually the third most abundant in numbers. The other groups comprised relatively low proportions. The lack of herbivores is indicative of the sparse vegetation in the study area.

Interstation Com arisons

Interstation comparisons were performed on a year-to-year basis by using larger groups of stations to detect divergent characteristics within one or more of these areas due to differential plant effect. The most logical approach was to first statistically compare the largest group of stations with similar substrate composition for both years. Stations 2, 4 and 5 were tested for each year by the Kruskal-Wallis test (Sokal and Rohlf, 1969). This is another'non-parametric test used to test for. differences among three or more groups (see Appendix Table L-2). This test was also applied to grab penetration estimates, number of taxa collected per replicate, and number of individuals collected per replicate. No significant differences (P=0.05) were found between stations for any of these parameters in 1976, but significant differences were found for all parameters in 1977. As expected,

Station 5 showed significantly less grab efficiency (penetration). However, number of taxa and number of individuals collected per replicate were significantly less at Station 4 during 1977 than during 1976.

C-26 Comparison of rarefaction curves supports these results P (Figure C-13). They indicate a close clustering of Stations 2, 4 and 5 in 1976 and a large degree of separation in 1977. This

separation is due to a slight increase in diversity at Station 2

and an even larger increase at Station 5 from 1976 to 1977.

A more rigorous method used for interstation comparisons is

the Morisita (1959) index of community similarity (CA,). This index is based on the abundances of cojoint (shared) species of taxa, total abundance in each sample, and respective diversity (see Appendix Table L-2). For this reason, it is being used extensively in benthic

analysis (Bloom et al., 1972; Heck, 1976 and 1977). CX represents

degree of faunal similarities between stations with a value of 1.0

expected between samples from the same community. A dendrogram can

be formed; which essentially reduces the data into clusters. The

group-average sorting method (Lance and Williams, 1967) was used in the present analysis and resulted in the formation of 'the major groups (Figure C-14). The first group, Station 3, 1976-77, exhibited the highest, similarity and therefore the greatest stability from year to year. The next major group was the shell-hash Stations 2,

4, 5 and 0 in 1976. Stations 2, 4 and 5 exhibited a tendency toward yearly continuity, although Station 5 in '1976 formed a separate subgroup. This finding supports statistical data and rarefaction results previously discussed for that station in 1977.

C-27 I I

I The beach terrace stations (1 in 1976-1977 and 0 in 1977) formed the third major group, although less faunal similarity was shown among these samples than among those of other groups., This is most likely due to 'the natural instability of the area. Previous studies of benthic arthropod fauna in this area indicated it to be inhabited primarily by transient species (Camp et al., 1977).

The only other major divergence found between years was observed at Station 5, which exhibited increased diversity and decreased similarity (CX) in 1977. Those changes resulted from significant increases in both number of taxa and individuals collected.

Concomitant increases in sediment mean grain size and sorting coefficient were also detected at this station, even though they were not significantly correlated (Spearman ranks, P=0.05) with the above parameters.

The above analyses indicate little unexpected change in station grouping from year to year which might be attributable to plant effect. The divergences observed are a result of increases in various community parameters at certain stations. These changes are most likely indicative of sediment heterogeneity rather than plant effect.

C-28 Com arisons With Baseline Benthic Studies

Baseline benthic studies were conducted during 1971 through

1973 at the same locations as the present study. These studies examined distributions of lancelets (primitive fish-like organisms;

Futch and Dwinell, 1977) and some aspects of the Arthropods, for the most part a crustacean community (Camp et al., 1977).

No significant differences were observed at any stations between studies. Similar tests were applied to benthic arthropod densities and diversities (d). Data from both studies were modified to exclude mieofaunal forms (i.e., Ostracoda, Halicarida, Copepoda and the isopod zicrocerberus sp.) which, because of their small size, were not quantitatively sampled. The only changes observed in these parameters were increases in density at Stations 1 and 5 during

1976-1977 and an increase in diversity (d) at Station 2 (Table C-7). These data suggest little long-term change (1971-1977) in benthic fauna from grab samples following plant construction and start-up.

The changes noted are in the form of increases.

Benthic Trawl Data

The following data are based on 22 months of. otter trawl collections at benthic Stations 0-5 from March 1976 through December

1977. During thi s period, 14,963 macroinvertebrates comprisi ng 209 taxa were identified. Of those, 5,923 individuals (164 taxa) were I I

I collected in 1977 and the remaining 9,040 specimens (156 taxa) were collected in 1976 (Appendix Table L-5).

Total numbers of taxa collected at each station during the 10- month period in 1976 and the same period in 1977 are presented in

Figure C-15. In 1976, collections from Stations 0 and 5 produced the highest numbers of taxa, 94 and 92, respectively. Station 3 produced the least with 33 taxa. Intermediate numbers of taxa were observed at Stations 1, 2 and 4. During 1977, Station 5 was again highest in number of taxa collected with 94 and Station 3 the lowest with 43. Stations 0 and 1 were comparable in 1977 with 69 and 63 taxa, respectively. Shell-hash stations (2, 4, 5 and 0 in 1976) exhibited a higher species richness in 1976 and 1977 than any of the other stations. Total species richness increased at all stations

(except Station 0, which was moved between 1976 and 1977).

Total abundances of macroinvertebrates at each station in 1976 and 1977 are presented in Figure C-16. Station 4 yielded the greatest number of organisms in 1976 with 3754, and Station 3 the least with 354. Station 1 also produced relatively low numbers, while numbers at trough Stations (0, 2 and 5) were relatively high.

During 1977, Station 5 produced the greatest number of individuals with 1867. Station 3 was again lowest with 354 organisms collected.

Stations 0 and 1 were comparable in 1977 with 703 and 813 specimens,

C-30 respectively. The number of organisms at four of the six benthic stations were similar in 1977; Stations 3 and 5 were the exceptions.

A substantial increase in abundance between 1976 and 1977 was observed at Station l. It is not known whether this increase was caused by natural population cycles, by differences in collection techniques or by the plant discharge acting as an attractant (e.g., by increasing food supplies). The total number of individuals collected at Stations 2 and 4 decreased in 1977 compared to 1976. These declines are not considered unusual since they probably reflect normal fluctuations in density of the dominant taxa.

The large seasonal variations in observed species richness (Figures C-17 through C-22) are attributable to the diversity, patchiness, and motility of benthic macroinvertebrate fauna and to the qualitative aspects of trawl collections. Although seasonal patterns varied among stations, maximum species richness usually occurred during the summer months of both 1976 and 1977. 'he pattern was marked somewhat by late fall and winter increases at

Stations 4 and 5 in 1977 and at Stations 0 and 5 in 1976. Except for these anomalous increases, trends of species richness at all stations generally followed observed patterns of bottom water temperature. Seasonal species richness at Station 3 most closely paralleled trends of mean bottom water temperatures. Species richness at that station was very similar between years, probably I

I indicating the presence of a more persistent, though less diverse, fauna than was found at the trough stations. Of the trough stations, Station 2 showed the least seasonal variation between years.

The most noticeable difference between years at Station 1

(Figure C-18) was a decline in species richness during late summer

(August and September) of 1977. This is the period when water temperatures reach seasonal maxima (Worth and Hollinger, 1977).

In 1977 Station 0, which is similar in water depth and substrate type to Station 1 but is 4.7 km south of it, showed no late summer decline in species abundance (Figure C-17). It is not known whether the observed disparity in species richness between Stations 0 and

1 was related to plant operation or to natural biological events.

Year-to-year differences in number of macroinvertebrate taxa collected were tested (Mann-Whitney U Test) at the six St. Lucie benthic stations. Numbers of taxa collected during 10 months of sampling in 1976 (March through December) at each benthic station were compared with trawl data from the same period in 1977. No significant differences between years were found, at any benthic station.

C-32 l Included among the taxa collected during 1976 and 1977 were seven species of comnercially important shellfish (Table C-8). Trawl catches of these species indicate, however, that they are represented by small populations which vary little from year to year.

The penaeid shrimp, Trachypenaeus constrictus, was collected in large numbers and does occasionally occur in corenercial catches of bait shrimp. However, it is usually of minor coranercial importance. r. constri ctus abundance data from trawl collections in

1976 and 1977 were pooled by station and are presented in Figure

C-23. A definite decrease in abundance was observed at all stations in 1977 compared to 1976. It is probable that the observed decreases were a result of natural changes in population density.

Juvenile recruitment occurred at Station 1 throughout the 2-year study period.

Monthly abundance data for r. constiictus indicate that six increases of abundance occurred at Station 1, but no definite seasonal patterns were evident when 1976 was compared to 1977 (Figure C-24). Seasonal abundance of T. c was similar I at Stations 0 and 1 in 1976 and 1977.

Dominant species at each of the six offshore stations were determined by using the "biological index value" of McCloskey (1970; Appendix Table L-2). To facilitate comparisons with 1976 data, values for January and February 1977 were excluded from ranking calculations. The five most dominant taxa, as well as their ranks by abundance and frequency at each station, are presented in Table C-9.

In most cases, taxa ranked among the top five by NcCloskey's

index were also ranked in the top five by abundance and frequency. Dominant species in trawl collections (as in grab collections)

showed a high degree of replacement from year to year. However, the dominant species (rrachypenaeus constrictus) at the discharge

and the control stations remained a dominant through both years of sampling. Plant discharge, therefore, has not enhanced a change of the most dominant epibenthic macroinvertebrate species in the surrounding area.

NcCloskey's index values were compared at each stat'ion. Sta-

tions 0, 1 and 3 were highly dominated by one or two species while

Stations 2, 4 and 5 exhibited a more gradual decrease through the

top-ranked taxa, indicating a more equitable distribution of dominance (Table C-9).

Dominance-diversity curves (Whittaker, 1965) depend solely on

the abundance of each species in a sample. Greater dominance (low

C-34 I diversity) is shown by a steeper slope of the upper portion of the curve. The dominance-diversity curves (Figures C-25 through C-30) produced a slightly different station relationship than McCloskey's index. These figures show that degree of dominance at all stations changed between 1976 and 1977. Dominance at Station 3 remained relatively constant in abundance over the two years of sampling.

A high degree of dominance was indicated for Station 4 due to the numerical dominance of rrejli ta quinquiesperZorata ~ Minol changes in dominance at Stations 2 and 4 probably reflect normal yearly abundance variations of dominant faunal components (crepiduza fornicata and Anomia simplex at Station 2 and H. quinquiesperZorata at Station 4) in conjunction with the qualitative aspects of trawl collections. The change in steepness of the curves for Station 0 reflects the loss of the dominant hard substrate fauna after the k station was relocated.

A major change was noted in the degree of dominance at Station

1 between years. The curves show only a small increase in total number of species between 1976 and 1977, but striking differences were noted in the abundances within the taxa. Undoubtedly, some of the increases .in abundance and number of species were attributable to large amounts of drift algae collected at Station 1 during the summer 'months of 1977. a Wilcox and Gamble (1974) discuss reasons for the high populations of H. quinquiesperforata on Pierce Shoal, near which Station 4 is located (Figure C-1) . C-35 The dominance curves for Station 5 were similar during 1976

and 1977. An increase in the abundance of individuals in 1977 may

have resulted from a situation similar to that described previously at Station 1. With the exception of the above-discussed disparities,

trawl macroinvertebrate dominance-diversity at each station showed little variation between 1976 and 1977. This indicates few possible changes in this parameter that could be associated with plant effect.

The Morisita index of community similarity (CA) was also used

to compare 1976 and 1977 trawl station data. The dendrogram formed using group-average sorting (Lance and Williams, 1967) indicated little faunal similarity during either year between Station 4 and all other stations (Figure C-31). In 1976, the trough stations (0,

2 and 5) formed a major group, with Stations 0 and 5 displaying the I highest degree of similarity between any two stations. The lack of similarity between Station 4 and the other trough stations was due primarily to large numbers of the sand dollar (ns. quinquiesperforata) collected at Station 4. A dendrogram formed by excluding this species (Figure C-32) showed that, during 1976, Station 4 joined the major group of trough stations and showed a very high degree of similarity with Station 5. Stations 1 and 3 in 1976 formed another major group and displayed low similarity with the trough stations.

C-36 I

I Consistent with their location in similar habitat and water depth, Stations 0 and 1 showed a very close similarity in 1977

(Figure C-31). A major perturbation at either station would be expected to alter the fauna, thereby decreasing the magnitude of the index value. Station 3 was also grouped with Stations 0 and 1 but had a relatively low similarity to either station. In 1977, trough

Stations 2 and 5 formed another major group, although the similarity between the stations was considerably lower than it was in 1976.

The displacement of Station 4 is presumed to be due to the same phenomenon discussed for 1976.

Morisita's similarity index was used to determine the degree of similarity between years at the same station. Station 4 had the highest similarity index (0.84) between years, probably because of the large and persistent sand dollar population. Stations 2 (0.35) and 5 (0.34) exhibited the lowest similarity values as a result of very diverse faunal assemblages with low numbers of shared species between years. Stations 0 (0.69), 1 (0.71) and 3 (0.76) formed a group with slightly lower values than that at Station 4. The faunal similarity index between years at Station 1 was comparatively high (0.71), indicating that community structure changed little during the first year of plant operation.

C-37 SUMMARY

Continued quarterly grab and monthly trawl sampling for benthic macroinvertebrates was conducted at six offshore stations in the

vicinity of the St. Lucie Plant. The first year of sampling was conducted in 1976 during the intermittent plant operation. During

the following year, 1977, the plant was operating most of the time.

Any plant-induced effects would therefore be observable by comparing data from the two study years. Additional sediment data from

older baseline studies, conducted in 1971-1973 were compared with the present study.

Macroinvertebrate composition by major taxonomic group exhib-

ited little change from 1976 to 1977. If plant effects were significant, the composition would be expected to change. Although the

dominant species fluctuated from year to year at all stations, a

relatively large portion of top-ranked species was shared by discharge

and control stations in 1977 when the plant was in full operation. This situation would not be expected if the discharge area were significantly stressed.

In the number of individuals or number of species collected, no

significant reductions were observed from 1976 to 1977. Some increases were noted.

C-38 Shipek grab data showed great seasonal variations in community structure (e.g., densities, number of species and biomass). Only Stations 3 and 4 exhibited recurring seasonal structural trends. The number of taxa shows significant positive correlation with density in the study area. Density trends for all stations (excluding 0) tend to be directly associated wi th mean bottom water temperature, although no significant correlation was determined. During 1977, densities and numbers of taxa declined at both the discharge and the control stations, indicati ng that variability on the beach terrace was normal rather than plant-induced.

Trawl sampling indicated that commercially important shellfish were represented by very small populations which showed little variation in numbers collected between 1976 and 1977. The penaeid shrimp,

Trachypenaeus constrictus, of little commercial lmpol tance, was the dominant species collected by trawling at both the discharge and control stations.

Three distinct substrate types were observed, each with a characteristic benthi c faunal assemblage. Station 1 was the only permanently sampled station to exhibit a significant change in sediment composition from baseline (1971-1973) through present studies. This change was an increased mean grain size during 1976. Although this might be attributed to discharge pipe construction, it I I

I is more likely a result of high-energy sediment transport on the beach terrace.

C-40 LITERATURE CITED

Abele, L. G. 1974. Species diversity of decapod crustaceans in marine habitats. Ecology 55: 156-161.

ABI. 1977. Ecological monitoring at the Florida Power 8 Light Co. St. Lucie Plant, annual report 1976. Vol. 1. AB-44. Prepared by Applied Biology, Inc., for Florida Power 5 Light Co., Miami.

Bloom, S. A., J. L. Simon, and V. D. Hunter. 1972. Animal-sediment relations and community analysis of a Florida estuary. Mar. Biol. 13:43-56.

Boesch, D. F. 1972. Species diversity of mar ine macrobenthos in the Virginia area. Chesapeake Sci. 13(3):206-211.

Camp, D. K., N. H. Whiting and R. E. Martin. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. V. Arthropods. Fla. Mar. Res. Publ. No. 25. 63 pp. Christie, N. D. 1975. Relationship between texture, species richness and volume of sediment sampled by a grab. Mar . Biol. 30:89-96.

Day, J. H., J. G. Field and M. P. Montgomery. 1971. The use of numerical methods to determine the distribution of the benthic fauna across the continental shelf of North Carolina. J. Anim. Ecol. 40:93-125.

Duane, D. B., M. E. Field, E. D. Meisburger, D. J. Swift and S. J. Williams. 1972. Linear shoals on the Atlantic lower continental shelf, Florida to Long Island. Pages 447-498 in D. J. Swift, D. B. Duane and 0. H. Pilken, eds. Shelf sediment transport. Dowden, Hutchinson and Ross, Inc., Strouds- bury, Pa.

Elliott, J. M. 1971. Some methods for the statistical analysis of samples of benthic invertebrates. Freshwater Biological Association. Scientific Publication No. 25. 144 pp.

EPA. 1973. Biological field and laboratory methods for measuring the quality of surface waters and effluents. EPA 670/4-73-001. C. I. Weber, ed. Environmental Protection Agency, National Environmental Research Center, Cincinnati.

Folk, R. L. 1966. A review of grain-size parameters. Sedimentology 6:73-93. I Fr ankenberg, D. 1971. The dynamics of benthic communities of Georgia, U.S.A. Thalassia Jugoslavica 7(l):49-55.

Futch, C. R., and S. E. Dwinell. 1977. Nearshore marine ecology at Hutchinson Island, Florida. 1971-1974. IV. Lancelets and fishes. Fla. Mar. Res. Publ. No. 24. 23 pp.

Gallagher, R. M. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. II. Sediments. Fla. Mar. Res. Publ. No. 23. pp. 6-25.

Gallagher, R. M., and M. L. Hollinger. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. I. Introduction and Rationale. Fla. Mar. Res. Publ. No. 23. pp. 1-5.

Gaufin, A. R., E. K. Harris, and H. J. Walter. 1956. A statistical evaluation of stream bottom sampling data obtained from three standard samplers. Ecology 37(4):643-648.

Hathaway, J. C. 1971. Data file continental margin program Atlantic coast of the United States. Vol. 2: Sample collection and analytical data. Woods Hole Oceanogr. Instit. Tech. Rep. Ref. No. 71-15. 54 pp. Heck, K. L., Jr. 1976. Community structure and the effects of pollution in seagrass meadows and adjacent.habitats. Marine Biology 35:345-357. Heck, K. L., Jr. 1977. Comparative species richness, composition and abundance of invertebrates in Caribbean seagrass (rhaz- assia testudinum) meadows (Panama). Mar. Biol. 41:335-348.

Lance, G. N., and W. T. Williams. 1967. A general theory of classi- ficatory sorting strategies. I. Hierarchial systems. Comput. J. 9:373-380.

Levinthon, J . 1972. Stability and trophic structure in deposit- feeding and suspension feeding cormunities. Amer. Natura- list 106(950):472-486.

Lie, U. 1968. A quantitative study of benthic in fauna in Puget Sound, Washington, U.S.A., in 1963-1964. Fisk. Dir. Skr. Ser. Haullnders. 14(5):229-556.

Lie, U., and J. C. Kelly. 1970. Benthic in fauna communities off the coast of Washington and in Puget Sound. Identification and distribution of the communities. J. Fish Res. Bd. Canada 27:621-651.

C-42 I I I

I I Livingston, R. J. 1976. Diurnal and seasonal fluctuations of organisms in a north Florida estuary. Estuarine and Coastal Marine Science 4:373-400.

Lloyd, M. J ., and R. J. Ghelardi. 1964. A table for calculating the "equitability" component of species diversity. J. Anim. Ecol. 33:217-227.

Lloyd, M. J., J. H. Zar, and J. R. Karr. 1968. On the calculation of information-theoretical measures of diversity. Am. Mid. Nat. 79(2):257-272.

Longhurst, A. R. 1959. The sampling problem in benthic ecology. Proc. N. Zeal. Ecol. Soc. 6:8-12.

McCloskey, L. R. 1970. The dynamics of the coranunity associated with a marine scleractinian coral. Int. Revue ges. Hydrobiol. 55(1):13-81.

Morisita, M. 1959. Measuring of interspecific association and similar ity between communities. Mem. Fac. Sci. Kyushu Univ., Ser. E (Biol.) 3(1):65-80. Rosenberg, R. 1976. Benthic faunal dynamics during succession following pollution abatement in a Swedish estuary. Oikos 27:414-427.

Sanders, H. L. 1968. Marine benthic diversity: A comparative study. Amer. Nat. 102:243-282. Siegel, S. 1956. Nonparametric statistics for the behavioral sciences. McGraw-Hill, New York. 311 pp.

Sokal, R. R., and F. J. Rohlf. 1969.'iometry. W. H. Freeman and Company, San Francisco. 776 pp.

Whittaker, R. H. 1965. Dominance and diversity in land plant communities. Science 147:250-259.

Wilcox, J. R., and H. Gamble. 1974. The ecological significance of marine animal populations of the Indian River Region. Harbor Branch Consortium, Indian River Study, unpublished annual report (1973-74) 2:293-332.

Worth, D. F., and M. L. Hollinger. 1977. Nearshore marine ecology at Hutchinson Island, Florida. 1971-1974. III. Physical and chemical environment. Fla. Dept. Nat. Res. Mar. Res. Lab. No. 23. pp. 25-85.

C-43 I

I Young, D. K., and D. C. Rhoads. 1971. Animal sediment relations in Cape Cod Bay, Massachusetts. I. A transect study. Marine Biol. ll:242-254.

C 44 I

I I 80 "15 '

V'l

:r f

C I, PIERCE ':;03'.,

SHOAL

~ ~ 04 ' '

~ 27'20~—

FPL ST. LUCIE PLANT O~ v',

O 0 00

Figure C-1. Locations of benthic macroinvertebrate sampling stations, 1977. I

I «LINE RING 0

'LYE I G HIE0 g ERAh'I

CI.OSING BAR ~ SCOOP HOUSING

HELICAL SPRING

ROEAT INC SCOOP

Fi gure C-2. Shi pek grab samp1 er.

C-46 I

I BASELINE OPERATIONAL

1 I I I I I I I I I I I I.O 08 ~ 0.6 m 04 o 0.2

Mar Jul Nov Mar Jul Mar Jun Sep Dec Mar Jun Sep Dec 1972 1973 1976 1977

Figure C-3. Mean g sizes and sorting coefficients of particle-size distributions for sediment samp'les taken at Station 1 in 1972-1973 and in 1976-1977, St. Lucie Plant. I

I 75 Station 1

50 // // // // --- —— Actual number of taxa 25 /I accumulated per replicate ,„ / / Gaufim cumulative / — taxa / plot'f / / 3 4 5 6 9 10 RUHBER OF REPLICATES

250

Station 5

~ 150 I

~~ 100 / / / // / / I ----- Actual number of taxa I accumulated per replicate I I I Gaufin cumulative I I plot, of taxa

1 2 3 5 6 NUHBER OF REPLICATES Figure C-4. Species saturation curves for benthic macroinvertebrates collected by Shipek grab at Stations 1 and 5, St. Lucie Plant, March 1977.

C 48

5.0 1.0

4.0

3,0

CC W 2.0

Equitability (e) 1.0 STATIei 1 Diversity (d)

1 2 3 4 5 6 7 8 9 10

NUHBER OF REPLICATES

Cl 3 .6 I I \/I OC CCI la> I 2 4J

Equitability (e) STATION 5 Diversity (8)

3 NUNBER OF REPL ICATES Figure C-5. Cumulative diversity (3) and equitability (e) for increased grab sampling at Stations 1 and 5, St. Lucie Plant, Parch 1977.

C-49 I

I STAT IOtl 1 STAT IOR ."

Oo 20 x15 6- lm x CC 15 VI I f3 4 4 W W VI VI CC O og 10 )W ) 5 2 H 2 o H

1 2 3 4 1 2 3 1 2 3 4' 2 3 4 1976 1977 1976 1977 SAttPLI,'tp QUARTER SAIIPL I 'tG t'tART E R

25 STATIOtt 2 25 STATIOIt 6 3 8 x 2p ~ 20 x < r r I 15 4 v xr 4 w-I P~15 VI Om dt'sWCC; O 10 2 ) 10 2 H

1 2 4 1 2 3 4 1 2 3 4 1 2 3 4 1976 1977 1976 1977 SAtctPL SACIPL IttG QUARTER , IttG QttARTER

8 20 8 STATIOR 3 8 STAT lptt tt x 6 x'5 I Ct r VI x r I VI / 4 r vI VI 1P rr W g / W 0 CL O 'cr Og 2 2 o ) 5 2 O H H

1 2 3 4 2 3 4 1 3 4 1 3 4 1976 1977 1976 1977 SAttPL IttG QUARTER SAIIPLlttG QUARTER

Density (number of individuals/m') ——--- Divers ity (d)

Figure C-6. Density and diversity of benthic macroinvertebrates collected by grabs at each of the six offshore sampling stations, St. Lucie Plant, 1976-1977. (Station 0 was relocated March 1977.)

C-50 Qi

l I

I Densi ty

CD p ——— Temperature CD CD I

CD / 0 V ~ 10 / 25 E / A, i( CY CA / \ / / / I— au / «C CD CY CD / laJ 5 // 20 CD I

M A M J J A S 0 N 0 J F M A M J J A S 0 N D 1974 1977

Figure C-7. Mean bottom temperature and mean density of macroinvertebrates collected by grab sampling at all offshore stations (excluding Station 0), St. Lucie Plant, 1976-1977. I

I POLYCHAETE AND HOLLUSC PLANKTONIC LARVAE 150

6 z 100 8 67.9

~ 40 C/j lal CD 30

< 20

CD CD BENTHIC POLYCHAETE.-HOLLUSC ADULTS

CCC G 10 8

5 I C/l 4J CD

M A M J J A S 0 N 0 J P M A M J J A S 0 N 0 1976 1977

Figure C-8. Mean benthic polychaete-mollusc densities collected by grabs at all stations (excluding Station 0) and meroplankton densities from surface and bottom net collections, St. Lucie Plant, 1976-1977. I 30

I \ I 28 I I I / I / l / I I I / I I 26 II~ / I / I

I / I I I I I \ I 24 I I / w I \ I \ I 4J / \ I / 'L / I K / I M g/ I 22 I I I I

18 ----- x bottom temperatures, Station 1 —x bottom temperatures, Station 0

M A M J J A S 0 N 0 J F M A M J J A S 0 N 0 1976 1977

Figure C-9. Mean monthly bottom temperatures at Stations 1 and 0, St. Lucie Plant, 1976-1977. STATION 4

STATION I 'ISO I 4 Ioo CL' CC W g so Z

Ioo 200 200 600 600 2,000 +000 NUMBER OF INDIVIDUALS NUHBER OF INDIVIDUALS

STAT IO.'I 2 STATIO'I 5

200 200 I I 4 6 200 Isl 06 Ul K IO0

2000 6,000 6000 Ivxo 2,000 6@00 NUHBER OF INDIVIDUALS NUMBER OF INDIVIDUALS

100 STATION 3 Ioo 0 I'll

0 so 06 4l CL'a) STATIONS 0 ond I K 60 1977

I 0 220 000 260 Iooo I260 ~00 600 NUMBER OF INDIVIDUALS NUHBER OF INDIVIDUALS Figure C-10. Rarefaction curves for offshore grab sampling stations indicating number of expected taxa for various population levels of benthic macroinvertebrates, St. Lucie Plant, 1976-1977.

C-54 I

I W%1093 tt ~ 470 W$ 7387 tt$ 1246 N%3884 N$8382

1977

$0 Ccl C7

0) ~ 20 20

C0 I Q1+ +~ CI QQ'4 QQ CQ OC yCC QQ Q~ ~+ ~~+ Q1'~ cQ Q~ CO >+ + Q< 4l 00 C0 W86751 tt*267 tt ~ 7747 N$ 907 N*5876 N 5758 Z 00

00 20 la) 1976

0 Stati OA 0 2 2 $ 5

Figure C-ll. Distribution by group of benthic macroinvertebrates collected by grabs, St. Lucie Plant, 1976-1977. STATION 0 STATION 3 100 00 4 V 4 OZ Others OZ 4I O 10 Carnivores WOCC 00 Osvcivores I CO I O Z cC Merbivores Z< 4l ~ 0 VW Deposit feeders VW 20 0C W 20 4I I Deposit-suspension feeders Wl C4O +0 C4 O 20 ':'.::::::::::::::~ '..:'.... -.".:'.:.:.: I Sos on

2 2 -I I 2 2 0 I 2 I 2 2 ~ 197d 1977 19715 1977 SANPLING QUARTER SAMPLING QUARTER

STATION I STATION e 100 100 10 14 V OZ 0 OZ WO '0 1 EII o ZO 00 00 I- O 10 ~ VW 0 VW4l CO Z~ 20 4I I aO 20 I I 10

I 2 2 ~ ~ 2 I 2 4 0 I 2 2 .0 197d 1977 197d 1977 SAHPLIIIG QUARTER SAHPLING QUARTER

STATION 2 STATION 5 100 100 00 ~0 4 Cl 41 OZ 00 OZ4.V 00 10 4l O 4l O 10 10 ~ Cl $0 I O 50 ~ 0 VW VW 00 0CW 20 20 '~ '~ 4I ~ I ; ~ , ',, , C4O 20 4I 10 I

2 c I 2 I 2 0 I 2 0 I 2 2 ~ 197d 1977 1975 1977 SAMPLING QUARTER SAHPLIHG QUARTER Figure C-12. quarterly percentage composition of macrofaunal feeding types collected by benthic grabs, St. Lucie Plant, 1976-1977. I I I I

I I I

I Station I

Station 0 Station S ~Station 2 Station 4 Station 2

Station 4

130

Station 1 Sa 1

Station 3 tati on Station I

1300

MUMIIR Of II40IVIOUALS MUMIER OF I'tOIVIOUALS Figure C-13. Rarefaction curves for the six offshore grab sampling stations indicating the number of expected taxa for various population densities of benthic macroinvertebrates, St. Lucie Plant, 1976-1977. I I 3 - Station 3 4 5 2 2 4 5 0 1 1 0 Yea r 1976 1977 1976 1976 1976 1977 1977 1977 1976 1976 1977 1977 Figure C-14. Dendrogram of similarities (CX) between station data for each year of benthic grab sampling. Group-average sorting was used to produce the observed clusters. I

I I

I I I I I ~ L ~ \ VL . LL

3P ~ 3P CD 0

25 ~ 25 ~

20 ~ 20 cL- CLj LLJ

15 ~ 15 ~

90 1976 1977

80 80

70 70 >C

60 60 C) C)

n m 50 50 I ~ Vl K 40 40

30 30

20 20

10 Ip

STATION 0 1 2 3 4 5 'STAT Iptl 0 I 2 3 4 5 Figure C-15. Total number of macroinvertebrate taxa collected by otter trawl at each offshore station, St. Lucie Plant, March-December 1976 and all months of 1977. Shaded areas represent number of taxa collected from March through December 1977. Ranges of bottom water temperatures measured for each year are indicated by station. Shaded areas represent ranges between March and December 1977. 3800 380~0

2000 1976 2000 1977

~ ~ ~ ~ 1800 1800 ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ 1600 1600 ~ ~

~ ~ ~

1400 1400 ~ ~ ~ ) ) ~ ~ 0 a ~ ~ ~ 1200 1200 ~ ~ ~

~ '4 ~ o 1000 ~ ~ ~ ~ ~ cY ~ ~ ~ ~ ~ 800 800 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ 600 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 200 ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ \ ~ ~ ~ ~ ~ ~ ~

~,tatinn 0 1 2 3 4 5 Station 0 1 2 3 4 5

Figure C-16. Total number of macroinvertebrates collected by otter trawl at each offshore station, St. Lucie Plant,'arch-December 1976 and all months of 1977. March-December 1977 are shaded for comparisons with 1976. I I I I

I I

I M ~ ~ ~ M

J / I / 'I r r IJ / 25 OC / 'I / I / r 'I / J ~e J C

ao \ 20 I

55 Ran9e of nontnly batten eater tesoeratores l5 ---Mean of eontnly aotton soter teeperatvres

~II

'10

tstR APR 1'AY 5ttt 5tl. A%i 5fP OCT leW OfC OAW 1f9 PAR APR PAT IRyt AL AVG tf9 OCT ROY OfC l916 1911 Figure C-17. Total number of macroinvertebrate taxa collected by monthly otter trawls with mean and range of bottom water temperatures at Station 09 St. Lucie Plant, March 1976 through December 1977. I

~ I A / / r 4/ / /' 2$ \ / w: w/ // \ / \ / 20 / I Ran9e of nonthly hotton water teeoeraturet -- -Nean of nonthly hotton water teeperaturet

ae K to

RAR APR RAY JIEI JOE AUG 6EP OCT ROY OEC JAII fE8 PAR AN PAY Jlel JOE AlC 6EP OCE IIOY OEC 1916 1977 Figure C-18. Total number of macroinvertebrate taxa collected by monthly otter trawls with mean and range of bottom water temperatures at Station 1, St. Lucie Plant, March 1976 through December 1977. / // / / EP /r 25 / I

2O —Range of aonthly oottoa eater testa/etures --- Steno Of annthly Oottoa sate/ teepeeetnret

o 15

Z a

NR APR tent JtN JN. AVG sf P OCT ROy OfC JAR 1 fe ttsR APR PAT Jgl Jll. AUG sf 0 OCT NOT OfC I916 1911 Figure C-19. Total number of macroinvertebrate taxa collected by monthly otter trawls and mean and range of bottom water temperatures at Station 2, St. Lucie- Plant, March 1976 through December 1977. I I / n // r ar / 25 / / aC rr e / IC

20 I

—Range of nontnly oottonnater teefaeraturee ---Nean of nontnty botton enter teeaaeratoree 25 15

l5 I

ae lo

NAR APR NAV JllN AUG 5EP JN. OCE NOV OEC JAN FEG PAR APR NAV AN JVC AllG 5EP OCE NOV OEC ) 915 1922

Figure C- 20 . -Total number of macroi nve rteb rate ta xa collected by monthly otter trawl s with mean and range of bottom water temperatures at Station 3 , St . Luci e Plant , March 1 976 through December 1 977 . IA I II J 25 J I «II J II 4C \ J a 20 a

Range of nontnly Ootton «ater teeoeratores Bean ntntnly totten «ater teeoeratores ao --- of

I c 20 CC

arR «ar 50t - 2tR 500 5!r oct Rny 0!C PRO fto «ae ayR rat .Ryt alR 500 5 0 oct 009 0!C 191! )911 Figure C-21. Total number of macroinvertebrate taxa collected by monthly otter trawls with mean and range of bottom water temperatures at Station 4, St. Lucie Plant, March 1976 through December 1977. I I I 25 r r r ra I \ r 20 K \ r —Range of oonthly button eater teepereturea l5 --- Mean of noathly hottoo eater teatereturee

me arR mt 0121 2u. R00 5fe oct h0v 0tt 2Re fts >ah arR rwv 2tra 012. 500 ttr oct R02 0fc 1915 19)2 Figure C-22. Total number of macroinvertebrate taxa collected by monthly otter trawls with mean and range of bottom water temperatures at Station 5, St. Lucie Plant, March 1976 through December 1977. I I I I

I I; I

I 1970 1977

II o 250 IIo

STAT IN I 2 5 5 STATION 0 I 2 4 Figure C-23. Abundance of Trachypenaeus constrictus in trawl collections all months combined (March-December for 1976 and January- December for 1977), St. Lucie Plant, 1976 and 1977. Shaded areas represent number collected between March and December 1977. I

I I I I 160 ~ St tf* 0 140 Statl 1

120

M A M J J A S 0 N 0 J F M A M J J A S 0 N 0 197b 1977 Figure C-24. Seasonal abundance of Trachypenaeus constrictus in trawl collections at Stations 0 and 1, St. Lucie Plant, 1976-1977. I.

I I I

I ,250 ~—0 NARCH-OECEIIBER 1976 0—0 NARCH-OECENER 1977

CO o 2.00

) 150

1.00 3 5 6 1 4 0.50 8

10 19

23 33

5 10 15 20 25 30 RANK OF SPECIES BASEO ON ABUNOANCE indicated Figure C-25. Dominance-diversity curves for trawl collections at Station 0, St. Lucie Plant, 1976-1977. When a given rank is shared by two or more taxa, the number of taxa sharing the rank is . I I

I 2.50

~ HARCM-OECEHBER 1976 ~ HARCM-OECEHBER 1977

1.00 3 2

28 26

5 10 15 20 25 30 RANK OF SPECIES. BASED ON ABUNOANCE Figure C-26. Dominance-diversity curves for trawl collections at Station 1, St. Lucie Plant, 1976-1977. When a given rank is shared by two or more taxa, the number of taxa sharing the rank is indicated . 2.50 ~—9 NRCH-RECEISER 1976 (numbers shown below line)

NRCH-RECEISEII 1977 2.00 ~ (numbers shown above line)

2 2 2 4 2 5 3 2 2 0.50 9 7 13 8

5 10 15 20 25 30 RANK OF SPECIES BASED ON ABUNOANCE Figure C-27. Dominance-diversity curves for trawl collections at Station 2, St. Lucie Plant, 1976-1977. LJhen a given rank is shared by two or more taxa, the number of taxa sharing the rank is indicated. I 250

HARCH-OECEHBER 1976 C) ~ 2.00 ~ HARCH-OECEHBER 1977 cC CI 1.50

1.00 2 3

2 5

0.50 4 5

'17 17

10 15 20 25 30

RANK OF SPECIES BASEO ON ABUNOANCE Figure C-28. Dominance-diversity curves for trawl collections at Station 3, St. Lucie Plant, 1976-1977. When a given rank is shared by two or more taxa, the number of taxa sharing the rank is indicated. l 3.50

2.50 ~ MARCH-DECEMBER 1976 C7 ~ MARCK-DECEMBER 1977 c 2.00

LSO CI

100 w 3 2 2 4 5 0.50 7 3

24 24

10 15 20 25 30

RANK OF SPEC?ES BASED ON ABUNDANCE Figure C-29. Dominance-diversity curves for trawl collections at Station 4, St. Lucie Plant, 1976-1977. When a given rank is shared by two or more taxa, the number'of taxa sharing the rank is indicated. ~ NARCN-DECENBER 1976 ~ NARCH-DECENBER 1977

2 2 4 2 2 5 3 4 3 3

17 12

30 26

10 15 20 25 30 35 RANK OF SPECIES BASED OM ABUNDANCE Figure C-30. Dominance-diversity curves for trawl collections at Station 5, St. Lucie Plant, 1976-1977. When a given rank is shared by two or more taxa, the number of taxa sharing the rank is indicated. I O.N

I916 l911

2 I 4 616'I I0;I 0 I 3 2 5 Figure C-3l. Dendrogram of similarities (CX) between stations for l976 and 1977 trawl collections. Group-average sorting was used to produce clusters. 5 0,30

OAO

0.50

0.60

0.70

0.80

0.90

STATION 4 5 0 2 I 3

Fi gure C-32. Dendrogram of s imi 1 ari ti es (CX) between s tations for 1976 trawl collections (excluding zelliea quinquiesperforata), St. Lucie Plant. Group ave'rage sorting was used to produce the observed clusters. I TABLE C-1

SUMMARY OF MACROINVERTEBRATE STUDY METHODS ST. LUCIE PLANT 1976-1977

Study Shipek sample and trawl Shipek sample Benthic grab sample ear stations and locations re licates Trawl sam les reservation

1976 0 - offshore trough 4/Station One 15-minute 10K buffered 1 - beach terrace tow/station/ seawater-formalin 2 - offshore trough month plus Rose Bengal 3 — Pierce Shoal stain 4 - offshore trough 5 - offshore trough

1977 0 - beach terrace 4/Station; One 15-minute Methanol crystals — 1 beach terrace plus 7 at Sta- tow/station/ added to sample 2 — offshore trough tion 1, and month prior to preserva- 3 - Pierce Shoal 4 at Station 5 tion, then as above. 4 - offshore trough during March 5 — offshore trough 1977 l

I l TABLE C-2

BENTHIC GRAB AND TRAWL STATION COORDINATES ST. LUCIE PLANT 1976-1977

Station De th m Latitude-Lon itude

7.6 27 21.2' 80 14.1',

11.3 27 21.4' 80 13.3'

7.6 27 21.7' 80 12.4'

11.3 27 20.6' 80 12.8'

11.3 27 22.9' 80 14.0'

Oa 8.2 27 19.1' 80o13.2'

a Station 0 was moved about 100 m inshore onto the beach terrace in 1977. This location was more representative of sediments found near the plant discharge's structure.

C-78 l

I ~ ~

TABLE C-3

BENTHIC GRAB HACROINVERTEBRATE AND STATISTICAL DATA BY STATION AND QlARTER OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Station and ear Nean 2 3 4 5 Paraneter tr. 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977

No. of taxa I 96 56 8 51 94 152 14 33 91 91 125 152 71.3 89.2 66.4 95.8 2 125 18 34 127 143 33 38 111 118 92 155 84.3 87.7 76.2 97.6 3 147 40 34 35 132 141 45 50 117 118 107 158 97.0 90.2 87.0 100.2 4 104 21 38 20 101 111 37 27 94 92 110 144 80.7 69.2 76.0 78.8 Total 260 109 75 99 249 259 84 84 219 203 236 303 Hean 118.0 38.7 24.5 34.7 113.5 136.7 32. 3 37.0 103.3 104.7 108.5 152.2

Density I 12042 4483 225 1933 10500 23917 817 858 8817 3817 8275 19425 6779 9072 5743 9990 (individuals/n>) 2 19292 3100 300 725 18308 14100 1892 2217 9350 9433 )4825 17033 10661 7768 8935 8702 3 14658 950 642 833 24150 14525 3458 6300 22892 12383 11983 17592 12964 8764 12625 10327 4 10267 575 1058 425 11600 9017 1392 1008 7908 6733 12900 15800 7519 5593 6972 6597 56259 9108 2225 3916 64558 61559 7559 10383 48967 32366 47983 69850 14065 2277 556 979 16140 15390 1890 2596 12242 8091 11996 17463

Hean raaker of I 482+146 179+110 94 3 77442 420+163 957+106 33+15 34412 353'157 153+ 17 331+ 66 777+440 individuals 2 772+299 124+ 71 12x 8 294 6 732+432 564+ 77 76453 89 14 3744102 118'2 593 175 681+188 per saayie 3 586+246 384 8 26+15 334 8 966t267 5814218 138+69 252442 916 181 495'100 479+ 59 704+201 4 411+112 23+ 7 42+11 174 6 4644 69 361+ 49 56+ 8 40 13 316+110 2694 45 5164105 632+365 Total 6751 1093 267 = 470 7747 7387 907 1246 5876 3884 5758 8382 TABLE C-3 (continued) BENTHIC GRAB HACROINVERTEBRATE ANO STATISTICAL DATA BY STATION AND DUARTER OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Station and ear ean I 2 3 4 5 1976 1977 1976 1977 Paraneter tr. 1976 1977 1976 1977 1976 1977 1976 1977- 1976 1977 1976 1977

97.303 5.100 2. 585 1.610 25.363 16.465 2.0&3 -1.233 3.453 0.795 7.460 17.695 23.041 7.150 8.189 7.560 Biomass (9/ma) I 6.242 10.531 2 11.985 0.718 3.815 5.795 8.643 9.178 2.240 16.548 10.558 7.800 5.953 13.335 7.199 8.896 2.880 7.060 0.995 13.400 9.273 14.100 1.975 4.105 2.643 19.000 6.498 16.220 4.044 12.314 4.277 13.365 3 48.493 4 10.910 2.620 1.865 1.120 6.080 7.460 1.765 5.320 3.695 1.090 3.200 227.475 4.586 40.847 3.321 Total 123.078 15.498 9.260 21.925 49.359 47.203 8.063 27.206 20.149 28.685 23.110 247.725 Hean 30.769 3.875 2.315 5.482 12.340 11.801 2.016 6.802 5.087 7.171 5.777 68.681 3.608 5.107 Diversity (3) I 4. 160 3.502 1.553 4. 808 4.218 5.523 3.025 4.345 4.161 5.464 5.111 5.397 3.705 4.840 4. 3.013 3.636 4. 480 4.522 5.291 3.184 3.360 4.690 5.108 4.244 5.622 4.113 4.479 4.055 4.772 2 400 4.539 3 5.389 4.479 4.423 4. 208 4.748 5.228 2.694 2.602 4.842 5.146 5.058 5.510 4.526 4.529 4.353 4 5.336 3.650 4.388 3.648 4.511 4.665 4.316 3.585 5.036 4.132 4.284 5.428 4.645 4.185 4.507 4.292 d/year 5.561 4.471 5.127 5.612 4.973 5.836 3.838 3.636 5. 279 5. 505 5.287 6.205 Hean 4.821 3.661 3.500 4.286 4.500 5.177 3.305 3.473 4.683 4.963 4.674 5.489 EquitabIIIty (e) I 0.273 0.291 0.464 0.817 0.291 0.454 0.81g 0.907 0.288 0.728 0.413 0.415 0.425 0.602 0.454 0.664 2. 0.249 0.299 0.997 0.970 0.267 0.410 0.391 0.386 '0.347 0.437 0.303 0.477 0.426 0.497 0.461 0.536 3 0.421 0.824 0.931 0.798 0.302 0.398 0.199 0.167 0.365 0 '48 0.465 0.433 0.447 0.511- 0.452 0.449 4 0.582 0.864 0.813 0.355 0.334 0.339 0.793 0.641 0.521 0.279 0.261 0.448 0.551 0.488 0.544 0.412 e/year 0.273 0.301 0.696 0.742 0.188 0.332 0.247 0.214 0.264 0.336 0.248 0.365 Hean 0.385 0.569 0.801 0.735 0.299 0.400 0.551 0.525 0.380 0.473 0.361 0.443

Total nurber of individuals collected at Station for year. TABLE C-4

SPEARMAN RANK CORRELATION COEFFICIENTS (P ) FOR VARIOUS COMBINATIONS OF NUMBER OF TAX DENSITY AND WATER TEMPERATURE AT FIVE OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Taxa vs. Taxa vs. Density vs. Density vs. Station densit tern er ature tern erature biomass

P 994** 0.000 -0.023 -0.072

0. 357 0.214 0.238 0.262

3 P 922** P 838** 0.500 0.095

0.819* 0.916** P 9 28** 0.386

0 714* -0.048 -0.167 0.714* All stat- tions combined '.667* 0.452 0.357 -0. 238 * Significant correlation (p=0.05); tabulated r =0.643 for n=8. ** Highly significant correlation (p=p.pl); tabulated rs=0.833 for n=8.

C-81 I

I TABLE C-5

MANN-WHITNEY U-TEST COMPARISONS OF GRAB REPLICATE DATA BETWEEN 1976 AND 1977 ST. LUCIE PLANT

Station Parameter

Grab efficiency *decrease *decrease NS *decrease

Number of taxa *decrease NS *increase NS *increase n Number of individuals *decrease NS NS NS NS *increase I CO = = * Significant at p 0.05. NS not significant. l

l TABLE C-6

TOP-RANKED DOMINANT TAXA OF BENTHIC MACROINVERTEBRATES FROM GRAB SAMPLES AT SIX OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Station and ear 0 1 2 3 4 5 Taxon 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977

NEMERTINA 10 1 1 1 4 2 4 8 3 5 3

ANNELLIDA Apoprionospio dayi Armandia agilis Axiothella mucosa Brani a vellfleetensi s Exogone dispar 4 Filogranula Sp. 1 4 10 1 2 1 1 Goni ada littorea Goni adi des caroli nae 7 6 5 6. 4 2 Hemipodus roseus Zoimia medusa Macrochaeta Sp. 10 Marionina SP. 9 5 Medi omastus cali forni ensi s 10 10 9 Oligochaeta 7 7 Parapi onosylli s longi cirrata 10 Peloscolex Sp.C 10 Polyci rrus eximius 10 Polygordius Sp. Pri onospi o cri stata Protodorvi 11 ea keferstei ni a Ranked according to McCloskey (1970) biological index values. I

I TABLE C-6 (continued) TOP-RANKEDa DOMINANT TAXA OF BENTHIC MACROINVERTEBRATES FROM GRAB SAMPLES AT SIX OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Station and ear 0 1 2 3 4 5 Taxon 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977

ANNELLIDA (continued) Protodri lus SP. Sabellari a vulgari s Sphaerosgllis SP. A Sphaerosgllis SP. Spio pettiboneae 10 Spirorbis SP. Sgllis spongi cola rharyx Sp. Tubificid sp. E Vermiliopsis Sp.

MOLLUSCA Caecum stri gosum Crasi nella dupli nana 1 1 Crasi nel1 a lunulata Crepi dula fornicata 9 7 Dentali um calamus 5 3 Glycemeri s spectrali s 2 2 Ischnochi ton hartmeyeri Ischnochi ton papi llosus Olivella floralia 3 Tellinairis s 4 2

a Ranked according to McCloskey (1970) biological index values. I

I I TABLE C-6 (continued) TOP-RANKED DOMINANT TAXA OF BENTHIC MACROINVERTEBRATES FROM GRAB SAMPLES AT SIX OFFSHORE STATIONS ST. LUCIE PLANT 1976-1977

Station and ear 0 1 2 3 4 5 Taxa 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977 1976 1977

CRUSTACEA Balanus venustus Cyclaspi s pustula Cyclaspi s vari ans Burydice littoralis 8 8 ~icrocerberus SP.A 10 Oxyurostyli s smi thi Protohaustori us SP.A 7 6 Pseudoplatyi shnopus sp.A 6 5 Syncheli di um americana 7 9 Tri chophoxus SP.A

SI PUN CULIDA 2 4 2 1 2 1 3 6

ECHINODERMATA Amphiodia pulchella 10 Clypeasteroidea 6 9 Ophiuroidea

CEPHALOCHORDATA Branchi ostoma cari baeum a Ranked according to McCloskey (1970) biological index values. I

I I

I TABLE C-7

MANN-WHITNEY U-TEST COMPARISONS BETWEEN 1971-1973a AND 1976-1977 GRAB DATA ST. LUCIE PLANT

Station Parameter

Lancelet density (no./m2) NS NS

Arthropod density (no./m2) *increase NS *increase

Arthro od diversit d NS *increase NS NS NS a Futch and Dwinell, 1977; Camp et al., 1977. * Significant at p=0.05. NS = not significant. TABLE C-8

COMMERCIALLY IMPORTANT SPECIES OF MACROINVERTEBRATES CAPTURED BY TRAWL COLLECTIONS ST. LUCIE PLANT 1976 AND 1977

Number S ecies Year ca tured Station

Penaeus duorarum duorarum 1976 43 0,4&5 1977 57 all stations

Sicyonia brevirostris 1976 21 0, 2, 3 & 5 1977 35 0, 2, 3, 4 & 5

Penaeus aztecus aztecus 1976 None 1977 12 0,1&5 Penaeus brasi liensi s 1976 0&5 1977 0&2

Penaeus sp. (juvenile) 1976 ll 0&1 1977 15 0&1

Calli nectes sapi dus 1976 0 & 1 1977 1

Meni ppe mercenaria 1976 1 1977 None

C-87 TABLE C-9

IXNINANT TRAWL SPECIES RANKEO BY NcCLOSKEY'S ANO ABUNDANCE INDEX'REQUENCY ST. LUCIE PLANT 1976-1977

1976 Rank Rank Rank Rank Rank Rank Station S ecies BIV 8 IV Fr . Fr . Abun. Abvn.

Trachypcnaevs constrlctus I 36.0 9 493 I 30.0 I 9 I 202 Crcpidula fornlcats 2 27.0 9 464 wellica quinqulesperforata 3 14.5 7 112 2 14.5 2 6 3 57 snonia sinplex 3 14.5 8 87 portunvs spininanvs 4 11.0 10 50 Trachypenaeus SP. 3 11.0 5 3 2 80 Turbo castanea 4 8.7 2 6 5 30 tel igo plei 5 7.0 5 3 4 54

Trachypenaevs constrictus 1 39.0 403 36.5 I 9 I 266 Sicyonla dorsalis 2 13.7 22 rcptochels sorrstorbits 3 8.1 14 4 10.5 3 5 5 27 Nellita quinqvicspcrforaca 4 6.0 14 Squills neglecCs 5 5.2 6 pcriclincncs longicaudatus 2 13.4 2 101 loligo plei 3 12.5 4 20 .rachypenacus SP. 5 8.0 6 110

Crepidvla fornicata I 40.0 I 1188 3 14.5 6 78 Trachyptnacus constriccus 2 25.5 3 98 2 17.0 1 40 anonfa sinplcx 3 19.5 2 171 portunvs spfninanus I7.0 4 92 5 10.5 1 27 processa hecphilli 5 7.2 13 9 periclinencs ionqicavdatvs I 20.6 2 147 loliyo plei 4 11.0 3 92 TABLE C-9 (continued) DDNINANT TRAWL SPECIES RNIKED BY HcCLOSKEY'5 INDEX FREQUENCY AND ABUNDANCE ST. LUCIE PLANT 1976-1977

1976 1977 Rank Rank Rank Rank Rank Rank Station S ecies BIV BIV Fre . . Fre . Abun. Abun. BIV BIV Fr . Fre . Abun. Abun.

Trachypenacus consCrictvs ) 39.5 I 9 I 76 I 28.3 I 8 2 52 Trachypcneopsfs nobflfspfnfs 2 16.5 2 6 32 2 27.5 I 8 I 83 Portunvs anccps 3 125 4 4 3 22 ' fcptochela serracorbfta 4 9.0 5 2 8 9 4 9.7 3 3 12 Cncope nichclfnf 5 8.5 4 4 10 4 Peri clintnes longieaudatus 3 11.0 2 4 7 14 l'roeessa SP.A 5 7.5 2 4 3 40

P'silica qufnqvfesperforata I 39.0 I I 3205 I 20.0 I 6 I 329 Trachypenacus cons trictvs 2 22.0 2 2 83 5 9.0 2 5 5 24 Chaetoplevra aplculaca 3 175 I 5 50 Portvnus spfnfnanus 4 12.0 3 6 47 nmnfa sfnplcx 5 95 5 3 76 Perfclfnenes longicaudaCus 2 16.5 I 64 Turbo casCanea 3 13.7 I 34 folfgo plcf 4 10.2 4 38 Crepidula fornicate I 36.0 2 9 I 449 Trachypenacus constrfcCus 2 27.0 I 10 2 171 Turbo castanea 3 18.0 2 9 3 133 2 18.0 I 10 6 122 anonfa simplex 4 14.0 4 7 4 126 Portunus spfnfnanus 5 120 2 . 9 6 82 tytcchfnus varfegatus I 23.0 I 10 5 128 Chaetopleura apiculata 3 16.0 4 7 7 90 arbaefa puncCulata 4 13.0 2 9 8 86 Chi one grus 5 9.0 6 5 9 56

a Biological index value (BIV). D. PHYTOPLANKTON

INTRODUCTION

The purpose of the phytoplankton study at the St. Lucie Plant was to monitor changes in phytoplankton density, relative abundance, pigment levels and productivity, and to examine the relationships between these factors and power plant operation. Therefore, changes in the phytoplankton component of the ecosystem at the St. Lucie

Plant were interpreted with regard to the physicochemical regime which existed at the time samples were collected, as well as to the potential influence of power plant operation.

Phytoplankton consists of passively drifting or weakly swimming algae. Benthic algae are frequently included temporarily in the phytoplankton. Due to limited motility, these microscopic plants are largely at the mercy of waves and currents in aquatic environments.

Excluding those organisms adapted to either very low or very high temperatures, most ogranisms live in the 0 to 45'C (32 to ll3'F) temperature range (Raymond, 1963). Major groups of algae vary in temperature tolerance ranges and temperature ranges for optimum growth and reproduction (Patrick, 1969). Drost-Hansen (1969) proposed that certain temperature ranges may exert a profound and sometimes dominating effect on biological activity due to physical changes in the structure of water. Ukeles (1961) reported maximum

0-1 l

I temperatures at which normal growth occurred in representative marine algae: Chrysophytes (yellow-brown algae), 24 to 27'C (75 to

81'F); diatoms, 24 to 30'C (75 to 86'F); and green algae, 27 to 35'C

(81 to 95'F). No growth was observed in any group at temperatures greater than 39'C (102'F), and return to marginal growth was greatly inhibited.

Because temperature optima and tolerance ranges vary, temperature is an important determinant in the seasonal succession of algal groups and species under natural conditions. Carpenter (1973) noted successional changes (increased dinoflagellates) in brackish-water phytoplankton after incubation in a pool which averaged 5.5'C (9.9'F) higher temperature than a control pool. Briand (1975) found that power plant entrainment reduced species diversi ty and disrupted phytoplankton community structure due to selective mortality of certain algal groups and enhancement of more tolerant species. Thermal addi tions to waters from power plants may alter natural seasonal patterns by causing an early onset of succession or even permanent/ alteration of species composi tion (Patrick, 1974). Since phytoplankters are primary producers, their abundance and communi ty composition either directly or indirectly influence the quantity and quality of all larger organisms that ultimately depend upon them for food.

Phytoplankton standing crop is determined by the dynamic inter- action of physicochemical parameters and by grazing pressure from

D-2 primary consumers. Physicochemical factors which may influence the spatial and temporal distribution of phytoplankton are water

temperature, light, nutrient availability, salinity, and currents

(Whitford, 1960). Because any of these factors may limit phytoplankton productivity or affect community composition and abundance, their

relationship to standing crop must be considered when evaluating the impact "of power plant operation.

The response of phytoplankton communities to thermal loading is due not only to increased temperature, but to the synergistic effects of various environmental factors associated with heated water. Investigators of this concept include Fisher and Wurster

(1973), Grayum (1971), Griffiths (1973), Roberts (1977), and Thomas and Dodson (1974). In general, these authors found that factors such as polychlorinated biphenyls, ionizing radiation, high light intensity, low nutrient levels, and chlorine, in combination with increased temperature, affected phytoplankton more adversely than increased temperature alone. Even when water temperatures are not elevated to the point of causing thermal death, synergistic effects may have a profound effect on phytoplankton productivity, species composition. physiology, etc., leading directly or indirectly to impact at higher trophic 1'evels.

Pertinent past studies concerning the effects of power plant cooling water on phytoplankton populations have been done by Briand

D-3

(1975), Eppley et al. (1976), Fox and Moyer (1973), Ricklef (1972), and NcKeller (1977). Results of these studies were varied, indicating that power plant effects must be assessed on an individual basis.

The San Onofre Nuclear Generating Station in southern California was chosen by Ricklef (1972) and Eppley et al. (1976) for investigations of effects on plankton. Based on the densi ty and diversity of plankton at affected and control stations, Ricklef found no detrimental plant-related effect on plankton. However, Eppley et al. recorded a 70 to 805 reduction in phytoplankton productivity at the outfall of this plant and concluded that power plant effects on entrained phytoplankton were due primarily to chlorine rather than heat.

Briand (1975) studied the effects of power plant cooling systems on marine phytoplankton at two southern California coastal power plants. Influent water temperatures ranged from 14'C (57'F) in January to 23'C (73'F) in August, and temperature rise in the condensers averaged 9.3'C (16.7'F). This investigator found that average phytoplankton mortality was 41.7% after plant passage. Entrainment reduced species diversity and disrupted phytoplankton coranunity structure due to selective mortality of certain algal groups and enhancement of more tolerant species. Diatoms were killed in greater numbers (45 .7/) than di noflagellates (32.8A).

D-4 I Fox and Moyer (1973) found that effects of increased water temperature on marine organisms at the Crystal River Power Plant,

Florida, were most profound immediately after heat exposure. These I investigators found that change in photosynthetic capacity was due to temperature increase and was dependent on the temperature of intake water. A decrease in productivity was observed when intake temperatures were 27'C (81'F) or greater, and as long as temperatures remained above 32'C (90'F), productivity values continued to drop.

Increases in productivity were recorded when intake water temperature was 24'C (75'F) and discharqe water temperatures did not exceed

32'C (90'F). The time of day samples were collected affected values more than plant effects. In a model simulation of a proposed nuclear unit at the Crystal River site, a maximum summer plume temperature of 98.6'F resulted in a projected 20K decrease in producer biomass 1 (McKeller, 1977). Selection of phytoplankton over benthic producers was indicated. However, McKeller suggested that water exchange in the environment acts as a stabilizing energy which moderates large fluctuations in planktonic populations and tends to stabilize the entire system.

MATERIALS AND METHODS

Ph to lankton Anal sis

Phytoplankton samples were collected monthly from surface and bottom levels of the water column at six offshore stations and in the intake canal. Only the surface level was sampled in the discharge

D-5 canal for samples taken after November 1976 (Figure D-1). Replicate

one-liter whole-water samples were collected at each station with a

pump (Figure D-2) designed to minimize damage to the phytoplankters.

Each one-liter water sample was preserved in the field with 5% buffered

formalin and returned to the laboratory. The preserved samples were

allowed to settle for a minimum period of 10 days before concentration. Whole-water samples were used in conjunction with the sedimen-

tation technique for qualitative analyses and quantitative estimates of standing crop.

Microscopic analysis was performed by the Utermohl (1958) tech-

nique with inverted compound microscopes equipped with calibrated ocular micrometers. Identifications and counts were made after the sample concentrates had settled a minimum of four hours in counting chambers. Phytoplankton species were enumerated at appropriate magnification by random field counts (EPA, 1973; APHA, 1971; Little- ford et al., 1940) in two identically prepared counting chambers per replicate sample. A minimum of one-half the entire counting chamber was examined to enumerate large and relatively scarce phytoplankters. Statistical analyses (hierarchical design analysis of variance) were used to determine the examined volume of sample concentrate necessa'ry to ensure 90% accuracy in counts at the 95% confidence interval.

D-6 I I I All phytoplankters, except some greens and blue-greens, were counted individually. Filamentous green and blue-green algae were measured in 100'tandard lengths with each length representing one counting unit. Colonial forms exclusive of diatoms were counted as each colony representing one counting unit. An average number of individuals per colony was specified where possible. Cells per

1 iter were cal cul a ted as N by:

—C Vc

N = —.

where: C = count

Vs= volume of sample concentrate (ml)

Vc= determined by multiplying the aliquot volume (ml) by the proportion of the counting chamber which was examined

Vi= initial sample volume (1)

A minimum of two individuals verified both qualitative and quantitative analyses for each group of monthly samples . Analysis of variance was used to determine significant differences between these individuals. If discrepancies were greater than 10K or if significant differences existed between operators at the 95% confidence level, counts were repeated. gualitative verification of new species was performed on each sample as new species were encountered.

All samples were retained in the Applied Biology laboratory as permanent vouchers.

D-7 l

I Samples for water chemistry were collected and physical measurements and weather observations were made concurrently with phytoplankton collections at each station. These data were examined as potential factors influencing phytoplankton populations.

Pi ment Anal sis

Replicate water samples for pigment determinations were collected monthly concurrently with phytoplankton samples. Samples were pumped from specified surface and bottom depths'at each station and transported to the laboratory as quickly as possible to minimize chlorophyll degradation.

Samples were processed according to the method of Strickland and Parsons (1972) and recommendations of Unesco (1966). Samples were filtered on the day of collection through Whatman GFC filters.

The filters were folded in half with the filtered particulates on the inside, immediately frozen under darkened conditions, and shipped in light-proof containers to the Atlanta laboratory for extracti on and analysi s.

Frozen filters from replicate samples were extracted by grinding in a 90K aqueous solution of spectrophotometric-grade acetone. The volume of the extract was measured and extinction values were read with 1-cm cuvettes in a spectrophotometer at a slit width of 1.0 nanome ter.

D-8 I

I I I Chlorophyll-a, -b, and -c concentrations were determined from readings at 665, 645, and 630 nm, respectively. Carotenoid concentration was determined from extinction at 480 nm. The amount of non-active chlorophyll-a, in terms of the quantity of phaeopigments present, was estimated from extinction at 665 nm one minute after acidification with 50Ã HCl. All extinctions were corrected by sub- tracting the turbidity reading at 750 nm.'xcessive turbidity readings were reduced by additional centrifugation. Results were obtained from the equations of Strickland and Parsons (1972), and chlorophyll and phaeopigment values were expressed as mg/ms. Carotenoid values were expressed as m-SPU (millispecified pigment uni t)/m .

RESULTS AND DISCUSSION

Nine divisions/classes of phytoplankton were observed in 1977 collections from the St. Lucie Plant area. These groups were I) Bacillariophyta (diatoms), 2) Pyrrhophyta (dinoflagellates), 3) Chlorophyta (green algae), 4) Cyanophyta (blue-green algae),

5) Euglenophyta (euglenoids), 6) Cryptophyta, 7) Chrysophyceae

(yellow-brown algae and silicoflagellates), 8) Haptophyceae (including coccolithophores), and 9) Prasinophyceae, plus one additional major group, consisting of unidentified phytoflagellates. Illustration of phytoplankton abundance and percentage composition for November and December 1976, not shown in the 1976 St. Lucie Annual Report (ABI, 1977), appears in the appendix of this report (Tables M-1 and

M-2; Figures M-I through M-3) .

D-9 I Ph to lankton Densit

Total phytoplankton densities ranged from a low of 86 x 10 cells/liter on the bottom at Station 2 in December to 9723 x

on the bottom at Station 1 in November (Tables M-310'ells/liter through

M-14). Average phytoplankton density was greatest in the intake canal and at Station 1, intermediate at Station 0, and lowest in

the discharge canal and at Stations 2, 3, 4 and 5. As in the 1976 collections, bottom populations were generally larger than surface populations. Phytoplankton density was greatest in November with maximum densities observed at most stations during this month (Figures

D-3 through D-14). Minimum phytoplankton abundance was generally observed in July and August. Phytoplankton populations were lower during the period February through September in 1977 than during a similar period in 1976, and average total phytoplankton density for

March through December of each year was lower at all stations during

1977 (Figure D-15). Annual differences in density could not be attributed to plant operational effect.

Whereas phytoplankton density at most stations in 1976 exhibited a bimodal pattern, with high populations in spring and fall, only the canal stations and Station 0 exhibited this pattern in 1977.

At offshore Stations 1, 2, 3, 4 and 5, only weak spring pulses or none at all were observed, resulting in a unimodal pattern at these stations. Although the bimodal phytoplankton cycle wi th peaks in spring and fall is typical of East Coast neri tie waters, natural I I I

I variation in this pattern is common. Turner and Hopkins (1974), in a study of the Tampa Bay System, found a unimodal seasonal pattern in one year and varied patterns in a second year. Phytoplankton density in the Indian River between Vero Beach and Fort Pierce showed various seasonal fluctuations (Youngbluth et al., 1976). Thus, annual diffelences in the phytoplankton seasonal cycle between 1976 and

1977 at the St. Lucie Plant were typical of natural variations in seasonal phytoplankton density; alterations attributable to power plant operation wet e not indicated.

Ph to lankton Communit Com osition Diatoms and phytoflagellates were the most abundant phytoplankton groups. Unidentified phytoflagellates were the dominant phytoplankton group in January and February but became, secondarily important as diatoms became dominant in March and April, comprising 12 to 18K of the total (Figures D-16 and D-17; Tables M-3 through M-6). Diatoms were also dominant during March and April 1976, but their relative abundance was much higher, 80 to 99% at most stations. During the remainder of 1977, phytoflagellates were dominant from May - August and in October, while diatoms were dominant in September, November and December (Figures D-18 through D-21; Tables M-7 through M-14).

Phytoflagellate dominance from May — August was also observed in

1976, excluding June when diatoms were dominant. In general, phytoflagellate relative abundance was higher offshore at the St. Lucie 'I I

I Plant in 1977 than in 1976, and this trend may represent a plant effeet on phytopl ankton species compos ition.

The most important species, in terms of abundance, throughout

the sampling interval were diatoms. Again, as in 1976, skeletonema costatum was the most abundant diatom. Diatoms, particularly skeletonema costatum, are the dominant phytoplankters in East Coast neritic waters (Carpenter, 1971; Marshall, 1976; Mulford and Norcross, 1971;

Patten et al., 1963; Smayda, 1957; and Turner and Hopkins, 1974) . Phytoflagellates sometimes achieve secondary importance (Youngbluth et al., 1976; Smayda, 1957) and, as Smayda noted, may exhibit negative association with diatoms.

Descriptions of synonymous species names and unidentified species appear in Tables M-15 and M-16. As in 1976, several trends in the abundance of particular species were noted (Tables M-17 through M-28).

Species observed to fall into one of the following three categories are summarized in Table D-1: 1) those observed only offshore, 2) those more frequently observed offshore, and 3) those observed only in the intake/discharge canals. ceratium f'usus, cgmbella spp., and sleuro- sigma elongatum exhibited a general shift in abundance from offshore to the intake/discharge canals within the May-June period. However, only fOUl species, Rhizosolenia alata f. indica, R. imbricata, R. stolterfothii, and Peridini um hirobis exhibited the same pattern in both 1976 and 1977 collections. I Upper lethal temperatures are known for four diatom species k found at St. Lucie: Chaetoceros laciniosus [29'C (84'F)], Ditylum brightwellii [>30 C (>86.0'F)], Ni tzschia acicularis [35'C (95'F)], and saeletonema costatum [34-37'C (93.2-98.6'F)] (Crippen,1974;

Saks et al., 1974; Hirayama and Hirano, 1970; and Drost-Hansen, 1969). The latter two species occurred frequently enough over the 2-year period to permit conclusions to be drawn. When the respective lethal temperatures of these two species were exceeded in the discharge canal, N. acicuZaris decreased in density between intake and discharge and increased between discharge and Station 1 surface, whereas s. costatum showed no pattern in either situation. Temperatures measured at offshore stations never exceeded the lethal range of either species and the densities of both species at Station 1 were generally comparable to those at the other offshore stations.

These results indicated a plant entrainment effect on N. acicularis, but no consistent pattern of offshore plant effect was observed for either species. As noted for total phytoplankton, the densities of both species were generally lower at all stations in 1977 than in 1976, but this was not indicative of plant effect.

D-13

Statistical Evaluation of Offshore Ph to lankton Data Analysis of variance for surface offshore stations indicated significant differences in phytoplankton abundance between months but not between stations; the same result was observed in 1976 collections (Table D-2). In 1977 phytoplankton abundance was significantly greater in November than in all other months, and in 1976 abundance was significantly greater in October than in all months except March (Table M-29). For the period March through December of both years, 1977 offshore surface phytoplankton densities were significantly less than those in 1976 (Table 0-3). Phytoplankton density for this period was significantly higher at Station 1 than at Stations 3 and 4 (Table M-30). Significant differences in phytoplankton abundance between months were indicated for bottom offshore stations in 1977 as well as in 1976 (Table D-2). As in surface collections; November 1977 and October 1976 showed significantly greater abundance than other months (Table M-31). In 1977,

Station 1 bottom was significantly greater than Stations 2 and 3 bottom (Table M-32). Offshore bottom phytoplankton density for the period March through December of both years was significantly less in 1977 than in 1976 (Table D-3). Station 1 phytoplankton abundance for this period was significantly higher than that at Stations 2, 3 and 4. Station 3 abundance was significantly less than that at

Stations 0 and 1 (Table M-30). I

I The foregoing data demonstrate an apparent stimulation of phytoplankton density at Station 1 due to plant operation. This stimulation may be caused by one or both of the following situations:

1) phytoplankton densities were higher in entrained canal water than at Station 1, and 2) phytoplankton reproduction was thermally stim- ulated in the vicinity of Station l. However, overall decreases in phytoplankton density at offshore stations in 1977 compared to 1976 may reflect annual variation in phytoplankton density rather than plant effect.

During the period March 1976 through December 1977, offshore surface phytoplankton density showed no significant correlations with chemical or physical parameters; however, offshore bottom phytoplankton density was significantly correlated with, phosphate and salinity (Tables D-4 and D-5). Curvilinear multiple regression for the same period indicated that temperature was the most important factor affecting offshore phytoplankton densities . However, temperature explained only 8'.6% of the variation in phytoplankton density, whereas nitrite and ammonia explained 18.1$ of the variation in phytoplankton density (Table D-G).

Entrainment and Tem erature Relationshi s

Comparison of changes in average phy'toplankton density between intake (Station ll) and discharge (Station 12) appears in Table D-7. Average populations in the intake canal ranged from 657 x 103 to 4857 x 10 cells/liter and in the discharge canal from 339 x 10 to

4431 x 10'ells/liter. The range in temperature change (aT) between

intake and discharge was +1.0 to +23.6'F (Table D-7). Whereas in

1976 no relationship between phytoplankton abundance and aT was discern-

ible, the sustai ned plant operational conditions characteristic of 1977 caused decreased phytoplankton densi ty in the discharge canal

in 10 of the 12 months studied.

Sustained plant operation may result i n alteration of the rela-

tive abundance of phytoplankton groups in the discharge canal and at Station l. Entrainment notably enhanced diatom relative abundance and reduced unidentified phytoflagellate relative abundance

in the discharge canal in all months except March, April and November (Tables M-3 through M-14). Proportionately greater phytoflagellate entrainment mortality was largely responsible for this change in relative abundance. During eight months, high or enhanced diatom

relative abundance in the discharge canal was associated with a diatom relative abundance that was higher at Station 1 than at Sta-

tions 2, 3, 4 and 5. Briand (1975) found that open ocean power plants in California could affect offshore phytoplankton species composition by enhancing certai n groups and reducing other s. The

large volume of offshore water available for exchange im the St.

Lucie area tends to stabilize and limit fluctuations in the phytoplankton population. The impact observed at the St. Lucie Power

Plant in 1977 is likely limited to the immediate vicinity of the offshore discharge at Station 1. D-16 Significant differences in canal phytoplankton density between months existed for both 1976 and 1977 collections (Table 0-8). Phy- toplankton densities were significantly higher in November than in all other months of 1977, indicating peak canal populations during this month (Table M-33). However, in 1976 October phytoplankton abundance was significantly higher than that in all other months except August, indicating that peak canal phytoplankton densities occurred earlier in 1976 than in 1977. These differences were attributable mainly to seasonal variation. There was no significant difference between intake and discharge stations in 1976, whereas in 1977 these stations exhibited a si gnificant difference; this change is indicative of a si gnificant plant-related decrease of phytoplankton abundance in the discharge canal. However, for the period March through December of both years, no significant overall difference was observed between stations (Table D-8). Phytoplankton densi ty in the canals was significantly correlated with temperature, nitrate and nitrite during the period March 1976 through December

1977 (Table 0-9). Curvilinear multiple regression for the same period indicated that nutrients, particularly phosphate, silica and ammonia, explained most of the variations in canal phytoplankton density (Table D-10).

Pi ment Anal sis and Primar Productivit Active chlorophyll-a concentration is widely used as an index of phytoplankton standing crop since this pigment is common to all

0-17 photosynthetic algae. Chlorophyll-a was highly correlated with phytoplankton density at the St. Lucie Plant, further emphasizing the . value of this pigment as an indicator of phytoplankton standing crop.

Chlorophyll-a values at offshore stations ranged from 0.18 mg/ms in July to 6.86 mg/ms in November at the surface, and from 0.29 mg/ms in June to 11.29 mg/m in November at the bottom (Table M-34). Sur- face values were slightly lower than bottom values. This trend was observed in 1976 (ABI, 1977) and in the baseline data (Worth and

Hollinger, 1977). Chlorophyll-a was significantly lower in 1977 than in 1976, although 1977 levels were comparable to baseline data.

Chlorophyll-a maxima for both surface and bottom at all offshore stations were observed in November (Figure D-22). Maximum chlorophyll-a was generally observed in October of 1976 at all stations. These

maxima October and November of 1976 and 1977, seasonal in respectively,'ere significantly greater than those in all other months, and analysis of variance for both years combined indicated significantly greater chlorophyll-a in September, October, and November than in other months (Tables D-ll, M-35, and M-36). Higher chlorophyll-a in these late fall months was also observed during the baseline study. These peaks in chlorophyll-a corresponded to periods of higher nutrient levels (nitrate, nitrite, and silica). Stepwise multiple regression indicated that variations in temperature, nitrate, nitrite, and silica were most important in describing changes in active chlorophyll-a, accounting for 47K of the variation (Table D-6). I

I I

I A significant negative correlation between chlorophyll~ and salinity was observed at offshore stations (Tables D-4 and D-5).

This negative relationship may reflect the influx into the sampling area of low-salinity estuarine water high in chlorophyll-a at Sta-. tions 1, 2 and 5, as observed during the baseline study. Conversely, intrusion of,oceanic water high in salinity and low in phytoplankton standing crop could also account for a negative relationship between chlorophyll-a and salinity.

Interstation comparisons between surface samples and between bottom samples indicated significantly higher surface chlorophyll-a at Station 1 than at Stations 3 and 4 and significantly higher bottom chlorophyll-a at Station 0 than at Station 3 (Tables D-ll and M-37). Significant interstation differences were not observed in 1976; however, when data from both 1976 and 1977 were combined, Station 1 was greater than Stations 3, 4 and 5 and Station 0 was greater than

Station 3 at the surface. At the bottom Station 0 was greater than

Stations 2, 3 and 4 and Station 1 was greater than Station 3 (Tables

D-12 and M-38). Clearly, phytoplankton standing crop is not impo- verished near the discharge. Chlorophyll-a at Station 1 is ei ther similar to or greater than chlorophyll-a at other offshore stations.

This may be the result of either 1) influx of estuarine water high i n chlorophyll-a, 2) local thermal stimulation of productivity resulting in high phytoplankton standing crop, 3) enrichment of the area around the offshore dischar ge from high chlorophyll-a levels in the intake canal, or 4) any combination of these three factors. Chlorophyll-a was generally higher in the intake canal than at offshore stations. Average chlorophyll-a was less in the discharge canal (Station 12) than in the intake canal (Station ll) during both 1976 and 1977 (Figure 0-23), although these differences were not significant. Chlorophyll-a in the canals exhibited seasonal and annual trends similar to those observed offshore (Tables 0-12 and M-39).

However, the fall maxima in the canals in 1976 and 1977 were not as pronounced with respect to other months as they were offshore. The significant negative relationship with salinity observed offshore was evident in the canals (Table 0-9). A weak negative correlation with temperature was observed; however, nutrients were most important in accounting for changes in chlorophyll-a (Table 0-10). Although a reduction in average chlorophyll-a due to plant entrainment was evident, this reduction was not great enough to reduce the higher chlorophyll-a levels in the canals below those generally observed offshore. Thus, water high in chlorophyll-a is discharged at Station

1 and may contribute substantially to the high chlorophyll~a observed in the surface samples at this station.

Phaeopigments are degradation products of chlorophyll and are thus an important indicator of phytoplankton destruction or normal algal cell death. As observed in 1976, phaeopigment levels offshore were greater on the bottom than on the surface (Figure 0-24) . A comparison of surface stations for both years indicated significantly hi gher phaeopi gment at Station 1 than at any other station (Tables 0-13

0-20 and M-40). For the 1977 data, stations were not significantly different at the surface, and phaeopigment levels on the bottom were significantly greater at Stati on 0 than at Station 3 (Table M-41). Signi- ficant monthly differences in phaeopigment reflected the seasonal variations observed for chlorophyll-a (Tables M-42 and M-43). These findings indi,cated that high phaeopigment levels were most closely associated with hi gh chlorophyll-a and were not indicative of a negative impact on phytoplankton standing crop in the offshore area.

Average phaeopi gment was slightly higher in the discharge canal during both 1976 and 1977. This is indicative of chlorophyll break- down in the discharge canal. However, significant differences between stations or between months were not observed.

Results of carotenoid and chlorophyll-b and -c analyses appear in Table M-44. Carotenoids are accessory photosynthetic pigments found in a large number of algal classes. Examination of the offshore variation in this widespread pigment yielded results which were essentially identical to those obtained from an examination of chlorophyll-a data (Tables D-4, 0-5, 0-6, 0-14 and M-45 through M-48).

Chlorophyll-c is a principal photosynthetic pigment found in diatoms, chrysophytes, cryptophytes, prasinophytes, and haptophytes, while chlorophyll-b is a principal pigment in green algae and euglenoids. These two pigments were examined in an attempt to evaluate ll

1 possible selective impact on either of these two algal assemblages.

Members of the chlorophyll-c group make up a significant percentage of the phytoplankton in the offshore area at the St. Lucie Plant and are therefore present during much or all of the year. Because of the widespread occurrence and abundance of the chlorophyll-c bearing group, patterns in interstation, seasonal, and annual variation, as well as relationships to physical and chemical parameters, generally reflected the findings observed for chlorophyll-a and carotenoid pigments: seasonal maxima in late fall, greater pigment levels in

1976, and higher bottom levels, wi th Station 1 greatest on the surface and Station 0 greatest on the bottom (Tables D-4, D-5, D-6, D-15 and

M-49 through M-52).

Chlorophyll-a exhibited no significant interstation differences at the surface. At bottom stations for both years combined, Station

0 was significantly greater than Station 4 (Tables D-16 and M-53). Seasonally, chlorophyll-b was generally greater in August through

November than in March through July (Tables M-54 and M-55).

Gross primary productivity was calculated from active chlorophyll-a and light data using the total curve of Ryther and Yentsch

(1956) for photosynthetic rate. An assimilation rate of 3.7 g carbon/hr/g chlorophyll was used. Solar insolation data for the site were not available for November and December 1977, so insolation values used in calculations were based on the average daily solar radiation for November and December 1976. I I I

1 I

I Productivity ranged from 0.10 to 0.70 g C/m~/day (Table M-56).

Results for November and December 1976 productivity calculations appear in Table M-57. As observed for pigments, productivity was less in 1977 than in 1976 (Figure D-25). Average productivity was lowest at Stations 1 and 3 and highest at Station 5. However, average productivity had a range of only 0.23 to 0.37 g C/m~/day, and no significant differences between stations were evident. Producti- vity was significantly higher in September than in May (Tables D-17 and M-58). Minimum productivity was also observed during'ay in

1976. As in 1976, this low productivity corresponded to the period of lowest chlorophyll-a and lower phytoplankton density. Maximum productivity was observed in September, but it should be noted that productivity for November, a period of maximum chlorophyll-a and phytoplankton density, could not be calculated because of zero light transmittance at bottom stations.

SUMMARY

Phytoplankton abundance and chlorophyll-a (an index of phyto-

plankton standing crop) exhibited a unimodal seasonal pattern at offshore stations in 1977. Both were significantly higher in Novem-

ber than in any other month. Seasonal maxima in 1976 were observed

h in October at offshore stations. Phytoplankton abundance and chlorophyll-a were greater on the bottom than at the surface during both years. Patterns in seasonal abundance and depth distribution of phytoplankton density and chlorophyll-a were similar to those

D-23 II

I observed in 1976 and did not indicate significant power plant influence. Both phytoplankton and chlorophyll-a abundance were less in 1977 than in 1976; however, these di fferences between years were attributable to normal seasonal variations.

The most- important components of the phytoplankton in 1977 were diatoms and unidentified phytoflagellates. Diatoms were also most important in 1976, and the diatom skeseeonema coseaeum was the most abundant phytoplankter during both years. However, during nine months in 1977, diatom relative abundance was enhanced and phytoflagellate relative abundance was reduced in the discharge canal and at the offshore station closest to the discharge (Station 1) as a result of phytoflagellate entrainment mortality.

Significant reductions in total phytoplankton density, decreased chlorophyll-a, and i ncreased phaeopi gment in the discharge canal were indicative of phytoplankton destruction. However, phytoplankton density and chlorophyll-a were generally higher in the intake canal than offshore.

Standing crop at Station 1 was not significantly reduced and was possibly enhanced due to thermal stimulation. Phytoplankton abundance was greater at Station 1 (closest to the offshore discharge) than at

the other offsh'ore stations. Density differences at Station 1 may be I 1 l attributable to plant effect. Interstation differences in relative abundance between intake and discharge and between Station 1 and the other offshore stations (2-5) were attributable to plant effect.

Chlorophyll-a and other pigments in general at Station 1 (sur'face)

and at the control Station 0 (bottom) were either similar to or significantly greater than those at other offshore stations.

Gross primary productivity was lowest at Station 1 and the station farthest from shore (Station 3). Lower productivity at

Station 1 was also observed in 1976. Minimum productivity in both years corresponded to the period of lowest chlorophyll-a and lower phytoplankton density.

Plant, effects on standing crop and relative abundance were limited to the discharge canal and Station 1. These effects were

ameliorated offshore by the mixing of large volumes of offshore water.

D-25 I I I I LITERATURE CITED

APHA. 1971. Standard methods for the examination of water and wastewater, 13th ed. American Public Health Association, Washington, D.C. 874 pp.

ABI. 1977. Ecological monitoring at the Florida Power & Light .Co. St. Lucie Plant, annual report 1976. Vol. 1 and 2. AB-44. Prepared by Applied Biology Inc., for Florida Power 5 Light Co., Miami.

Briand, F .J.-P. 1975. Effects of power-plant cooling systems on marine phytoplankton. Mar. Biol. 33:135-146.

Carpenter, E.J. 1971. Annual phytoplankton cycle of Cape Fear, North Carolina. Chesapeake Sci. 12:95-104.

Carpenter, E.J. 1973. Brackish-water phytoplankton response to temperature elevation. Estuarine and Coastal Mar. Sci. 1(1):37-44.

Crippen, R.W. 1974. Same thermal effects of a simulated entrainment regime on marine plankton. Ph.D. Thesis, Univ- ersity of Maine. 113 pp.

Drost-Hansen, W. 1969. Allowable thermal pollution limits - a physico-chemical approach. Chesapeake Sci. 10:281-288.

EPA. 1973. Biological field and laboratory methods for measuring the quality of surface waters and effluents. EPA 670/4-73-001. Environmental Protection Agency, National Environmental Research Center, Cinn.

Eppley, R.W., E.H. Renger, and P.M. Williams. 1976. Chlorine reactions with seawater constituents and the inhibition of photosynthesis of natural marine phytoplankton. Estuarine and Coastal Marine Science 4:147-161.

Fisher, N.S., and C.F. Wurster. 1973. Individual and combined effects of temperature and polychlorinated biphenyls on the growth of three species of phytoplankton. Environ. Poll. 5:205-212.

Fox, J.L., and.M.S. Moyer. 1973. Some effects of a power plant on marine microbiota. Chesapeake Sci. 14(1):1-10.

D-26 Grayum, H. 1971. Effects of thermal shock and ionizing radiation on primary productivity. NTIS No. CONF-710501-Pl. Proc. Third Nat. Symp. on Radioecology, Oak Ridge, Tenn. 1:639-644. Griffiths, D.J. 1973. Factors affecting the photosynthetic capacity of laboratory cultures of the diatom maeodachylum tricornutum. Mar. Biol. 21(2):91-97.

Hirayama, K., and R. Hirano. 1970. Influences of high temperature and residual chlorine on marine phytoplankton. Mar. Biol. 7:205-213.

Littleford, R.A., C.L. Newcombe, and B.B. Shepherd. 1940. An experimental study of certain quantitative plankton methods. Ecology 21(3):309-322.

Marshall, H.G. 1976. Phytoplankton distribution along the East Coast of the USA. I. Phytoplankton composition. Har. Biol. 38:81-89.

HcKellar, H.N. 1977. Metabolism and model of an estuarine bay ecosystem affected by a coastal power plant. Ecological Modeling 3:85-118.

Hulford, R., and J. Norcross. 1971. Species composition and abundance of net phytoplankton in Virginia coastal waters, 1963-1964. Chesapeake Sci. 12:142-155.

Patrick, R. 1969. Some effects of temperature on freshwater algae. Pages 161-185 in P.A. Krenkel and F.L. Parker, eds. Biological aspects of thermal pollution. Vanderbilt University Press, Nashville, Tenn. 407 pp.

Patrick, R. 1974. Effects of abnormal temperatures on algal communities. Pages 335-349 in J.W. Gibbons and R.R. Sharitz, eds. Thermal ecology. NTIS No. CONF-730505. Technical Information Center, U.S. Atomic Energy Commission, Oak Ridge, Tenn. 670 pp. Patten, B.C., R.A. Mulford, and J.E. Warinner. 1963. An annual phytoplankton cycle in the lower Chesapeake Bay. Chesapeake Sci. 4:1-20.

Raymont, J.E.G. 1963. Plankton and productivity in the oceans. Pergamon Press, N.Y. 660 pp.

Reid, G. K. 1961 'cology of inland waters and estuaries. Reinhold, New York. 719 pp.

D-27 I gi l g 1

-S

I' Ricklef, R. 1972. The thermal effects on plankton at the San Onofre Nuclear Generating Station. M.A. Thesis, California State College, Fullerton. 63 pp. University Microfilms, Ann Arbor, Mich. (M-3458). Roberts, M.H., Jr. 1977. Bioassay procedures for marine phytoplankton with special reference to chlorine. Chesapeake Sci. 18(1):130-136.

Saks, N.M., J.J. Lee, W.A. Muller, and J.H. Tietjen. 1974. Growth of s'alt marsh microcosms subjected to thermal stress. Pages 391-398 in J.W. Gibbons and R.R. Sharitz, eds. Thermal Ecology. NTIS No. CONF-730505. Technical Information Center, U.S. Atomic Energy Commission, Oak Ridge, Tenn. 670 pp.

Smayda, T.J. 1957. Phytoplankton studies in lower Narragansett Bay. Limnal. Oceanagr. 2:343-359.

Strickland, J.D.H., and T.R. Parsons. 1972. A practical handbook of seawater analysis. Fish. Res. Bd. Canad. Ottawa, Bulletin No. 167. 310 pp.

Thomas, W.H., and A.N. Dodson. 1974. Effect of interactions between temperature and nitrate supply on the cell-division rates of two marine phytoflagellates. Mar. Biol. 24:213-217.

Turner, J.T., and T.L. Hopkins'974. Phytoplankton of the Tampa Bay System, Florida. Bull. Mar. Sci. 24:101-121.

Ukeles, R. 1961. The effect of temperature on the growth and survival of several marine algal species. Biol. Bull. 120(2):255-264.

Unesco. 1966. Determination of photosynthetic pigments in seawater. United Stations Educational, Scientific, and Cultural Organization. Place de Fontenoy, Paris-7. 69 pp.

Utermohl, H. 1958. Zur vervollkommung der quanti tativen phytoplankton- methodik. Mitt. Int. Ass. Theor. Appl. Limnol. 9. 38 pp.

Whitford, L. C. 1960. Ecological distribution of fresh-water algae. Pages 2-10 in C. A. Tyron, Jr., and R. T. Hartman, eds. The ecology of algae. Spec. Publ. No. 2. Pymatuning Laboratory of Field Biology, Univ. of Pittsburgh, Pa. 96 pp.

Worth, D.F., and M.L. Hollinger. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. III.Physical and chemical, environment. Fla. Dept. Res. Mar. Res. Lab. No. 23. pp. 25-85 .

D-28 Youngbluth, M., R. Gibson, P. Blades, D. Meyer, C. Stephens, and R. Mahoney; 1976. Plankton in the Indian River lagoon. Pages 40-60 in O.K. Young, ed. Indian River coastal zone study 1975-1976, annual report. Volume One. Harbor Branch Consortium, Fort Pierce, Florida. 187 pp.

D-29

80 "15 '

1 km

~ Q' g

I '') ~ . ~ I Q4

O 27'20~—

FPL ST. LUCIE PLANT Og l~ O

O Qp 0

Figure D-1. Locations of phytoplankton sampling stations, 1977. 1 ~ ' C VC CATE VALVE

INTA KC

VATCA SLOW

IIC'ATC VALVCq

I L RESERVOIR VATEA CLOD

WNOLC WATCA OAOTLE ACIIOVTO

IC VOLT IVACLLENOIAIA

OITCIIAAAE

~AOeCTIO.AL rVO,

O r r ACALC

Fi gure D-2 . Pump des ign for whole water sample collections at the St . Luci e Plant .

Temperature data points connected for visual continuity only.

11 SOPHIC

ll 1I NIIOI ll5aWKI COL StlllDS +/5HNE NI%N SIN IO6

Figure D-3. Phytoplankton density and water temperature, St. Lucie Plant, 25 January 1977. I I Ii I,

I Temperature data points connected for visual continuity only.

IISSIISI IIISIISI 12 44IIKI 4 I I I 4 aIS444 SSIISI SIIIII4S III&4%4444I IIII444

Figure D-4. Phytoplankton density and water temperature, St. Lucie Plant, 15 February 1977. 5 Temperature data points connected for visual continuity only.

~ 24

IISOCKS llIOTOI St SOIOC I 2 2

CIWL SIOIOS 4IIIKNC OOIOI SltTTOO

Figure D-5. Phytoplankton density and water temperature, St. Lucie Plant, 11 March 1977. 5 Temperature data points connected for visual continuity only.

~ I

II$W'KE 11 INIOI IS $IWICC ~ $lklIWl

Figure D-6. Phytoplankton density and water temperature, St. Lucie Plant, 19 April 1977.

Temperature data points connected for visual continuity only.

3 3 1 1 4NSOE 141 KE $IVIO5 OffP0% l0llOI5IETgkj

Figure 0-7. Phytoplankton density and water temperature, St. Lucie Plant, 10 May 1977. Temperature data points connected for visual continuity only. ~ $

l~ I

Cl g Il

2.'I~ 2

NOICC ~ I NOVI IlNo$$$ 2 COO $ $$IOOI OIOOC OOIKC IIIII'IOOCNIIOIOIIIOO

Figure D-8. Phytoplankton density and water temperature, St. Lucie Plant, 14 June 1977. II 7

~ — ~ Temperature data points connected for visual continuity only.

II OSSKI IIKfftOI lt SIAfKI O 5 l 5 \ CNW STITIOO OffSOK SISSKS STSTSSK OTT5TOK NttO lfltlIO5

Figure D-9. Phytoplankton density and water temperature, St. Lucie Plant, 12 July 1977. I Temperature data points connected for visual continuity only.

~ l

~ t

4tflOK !UVRE PilWa

Figure D-10. Phytoplankton density and water temperature, St. Lucie Plant, 23 August 1977. l

I Temperature data points connected for visual continuity only.

IIZNFKC IIIOI1OI IIQSfKl

CINE t!NN%

Figure D-11. Phytoplankton density and water temperature, St. Lucie Plant, 13 September 1977.. Temperature data points connected for visual continuity only.

I.S

II QSIISE II NflSI II SWISS ~ SISS IOS

Figure D-12. Phytoplankton density and water temperature, St. Lucie Plant, 11 October 1977. I I

I I I

I IS

Temperature data points connected for visual continuity only.

IISWISS IINSISI IIIIIIISI 4 I I I IIIIIIIIINLL IIISISI KSSSI IIIIIOII

Figure D-13. Phytoplankton density and water temperature, St. Lucie Plant, 2 November 1977. ~ I

I Temperature data points connected For visual continuity only.

1 I StVKC llSffNI llSVfKC 1 S CNNL ltVSSSS SfftKIC SfVKC SfVSCSS KSSKK SfftOI S SSSSK

Figure D-14. Phytoplankton density and water temperature, St. Lucie Plant, 1 December 1977. I

I I I

I I 3.5

2.5 1976

1.,5 1971

0.5

CANAl STATIONS

35 C> X 2.5

l.S

O.5

O 2 'g OFFSHORE SURFACE STATIONS

2.5

1.5

O.S

OFFSHORE BOTTOH STATlONS

Figure D-15. Comparison of average total phytoplankton density, St. Lucie Plant, March-December 1976 and 1977.

D 44 ~ p

gE \'.:::A

Percentage composition based on average density of surface and bottom samples.

4 Percentage composition based .on single-depth samples collected in immediate discharge.

Any group representing <5% of the total density was included in the OTHERS;category. TS OAICIAT II11

IIAvy 125 0 I 2 5 0 2 4 5 CNNL STATIONS Offffeff IIFAFACE STATICAS OfFSIOAC COlfCII STAIICAS

, r I

E% TS FTIAOAAT If11

I'I I t

0 I 125 0 0 I 2 4 5 0 2 4 5 CAIAL STAT IOIS OFFSHCAC SOAFACT STATIOIS FftSIIFAE IOTTOI STATIOAS Figure D-16. Phytoplankton percentage composition at the St. Lucie Plant, 25 January and 15 February 1977. Percentage composition based on average density of surface. and bottom samples.

Percentage composition based on single-depth . samples collected in immediate discharge.

Any group representing <5C of the total density was included in the OTHERS category. ll NAACN lff1

ITAv0 F250 I 2 4 0 I 2, 2 S CAVA STATIOFS OFFSFONC S4IFACC STAfICNS OFFSNOAC SOTICFI 1'fATIONS

IF AFAIC 1111

0 v b IIAvy 12 S 0 2 5 0 I 2 A 5 CATAC STATICNS OFFSNONC SOAFACC STATIONS OFFSNOAE SOTTCFF STATIONS Figure D-17. Phytoplankton percentage composition at the St. Lucie Plant, ll March 1977 and 19 April 1977. Percentage composition based on average density of surface and bottom samples.

Percentage composition based on single-depth samples collected in immediate discharge.

Any group representing <5Ã of the total density was included in the OTHERS category. 10 OAT Iff2

0 IIAvg 12$ 0 I 2 I 2 3 ~ 5 CAW. STATIOIS 0, OFFSFO|E SOAFACE STAIIOTS c OFFSAOAE TOTTNI STATIONS

e e

I~ OOFE ISTT,

IfAvg '12$ 0 I 2 5 0 I 2 3 4 5 CAAAC STATIOTS OFFTFOAE 512fACE STATIONS OFFIFFTAE OOTI01 STAIIOAS Figure 0-18. Phytoplankton percentage composition at the St. Lucie Plant, 10 Hay 1977 and 14 June 1977. Percentage composition based on average density of surface and bottom samples.

Percentage composition based on single-depth samples collected in immediate discharge.

Any group representing <5% of the total density was included in the OTHERS category. " ITAL 12S 0 0 I 2 5 0 I 2 5 CAAAL STATIC@I OfFSNOAC SOAFACC STAT TOTS CFF00aC SOTISC SIAIIOTS

21 ACCOST ltff

ITAL 12S 1 2 3 5 0 I 2 3 4 5 CACCIA SIATIOAS OFF%OAT SCAFACC STATICS OFF&OAT COTTONY STATICS Figure D-19. Phytoplankton percentage composition at the St. Lucie Plant. 12 July 1977 and 23 August 1977. Percentage composition based on average density of surface and bottom samples.

Percentage composition based on single-depth samples collected in immediate discharge.

Any group representing <5Ã of the total density was included in the OTHERS category. M W M M M W W W

TS SEFTITOER 1911

0 IIAvy 125 I 2 0 I 2 3 5 CATAE STATECRS OFFSRORE SNFACC STATE CRS ~ OFFSRORE ROTTCFE STATECRS K%P

ll OCTCRtR llll

II~A 1250 0 I 2 5 0 I 2 5 CASAL STATIORS OFFSRSRE SIRFACE STATIOCS OFFSTORE SOTTO'TATICOS Figure 0-20. Phytoplankton percentage composition at the St. Lucie Plant, 13 September 1977 and ll October 1977. Per'centage composition based on average density of surface and bottom samples.

Percentage composition based on single-depth samples collected in immediate discharge.,

Any group representing <55 of the total density was included in the OTHERS category. I TOSITOCA ISTT

0 4 0 I 2 3 4 5 IT A~ 123 0 I 2 3 5 CLVC STAITOTS OffSfTTAC SVRtACI SIAITOTS OfTIIIOAC TOITCIT 5TAT1 015

I OCCCTOCA 1111

ITAL 123 0 'I 2 4 5 0 I 2 5 CASAC 5TATTOTS OTTSfOAC SCOfACC STATTOTS OffSAORE OOITOfl SIAIIOAT Figure D-21. Phytoplankton percentage composition at the St. Lucie Plant, 2 November 1977 and 1 December 1977. I l

~, I (1929( STATION 3 10 STATION 0

I1 I ~ ~ 1 ~ ~ I 1 ~ ~ 1976 I 1 ~— ~ 1976 I I 1 I 999 I 1999 I 1 I 1 6 I 1 I I 1 I I 1 I I 1 I I I 6 I ~ 1 I I I ( I 1 I I I \ I 1 I I I \ 1 I I 1 I g 1 I g k g 1 I I / 1 I / I I I ~ ~ I ~ ~ 1 ~ 4 I I r I 6 ~I 0 0 0 J F M A M J J A S 0 N D J F M A M J J A S 0 N D J F M A M J J A S 0 N 0 J F M A M J J A S 0 N D

10 0".I 4 STATION I STAT I 9 I / 1 I 6 8 1 1 g 1 6 '1 I 1 7 7 1 I 1 I I 6 I 6 1 I1 \ I Fi I I S g \ I 1 O I 1 g 1 I I 1 1 I OCg I I g 4 I I I I '1 I 1 I 1 I I 1/ I '1 I 1 I I I \ I 1 I 3 3 1 1 \ I I 1 ) 1 I 1 \ I \ I v-< I 1 I I \ 1 \ 2 9/ 2 I \ I \ I P--~ \ I \ g '1 I \ / I / 1 I '1 / I( 0 J F M A M J J A= S 0 N D J F M A M J J A S 0 N D J F M A M J J A S 0 N D J F M A M J J A S 0 N D

STATION 2 STATION 5

~ 1 II ~ I 1 I ~ I 1 I 1 1 I I I 1 ~ ~ I I 1 I I 1 ~ I g 1 I 1 I I I 1 I 1 I I 1 1 I I 1 1 1 Ig I I g( \ / I / \ II I I ~ 1 I I I I \ r S--A \ r / / 0 J F M A M J J A S 0 N D J F M A M J J A 6 0 N D J F M A M J J A S 0 N D J F M A M J J A 6 0 N D SURFACE BOTTOM SURFACE BUTTON Figure D-22. Active chlorophyll-a concentration for offshore stations at the St. Lucie Plant, March 1976-December 1977. I Q 160 160 i ~ ~ 1976 8 t o 120 977 6 120 I I I I I I I I I I I I I I \ I I I ap I I I 80 ~D I I I \ CL I I I \ I \ I \ I \ I W ) 40 4p I / EJ 6 ';/

J F M A M J J A S 0 N 0 J Fi M A M J J A S 0 N 0 50

40 40

3.0 30 6 6 2P 2.0

I 4l 1.0 10

I \ I I I I 05 I I 'I 05 P I I / I / I I I \ / % //

J F M A M J J A S 0 N J F M A M J J A S 0 N 0 STATION ll ( ltlTAKE CANAL) STAT!ptl l2 (O(SCHARGE CANAC) Figure D-23. Active chlorophyll-a and phaeopigment concentrations for intake and discharge stations at the St. Lucie Plant, March 1976-December 1977. (get/dct) JN3N91d03VHd o 0 0 0 0 0 Q 0 0 0 0 0 o o 0n a 0 0 c4 0 r r r O' rr 0 0

'ta.

S- Cl JD E tS) CO I (U C 1 C) crt I

Cll

0 0 0

QJ ~ 0c

Q 0 Q 0 0 0 0 Q Q 0 0 0 o a R g 0 e 0

S O 0 Q 0 0 a o 0 0 0 0 0 0 0 0 8 c4 0 e r 0 A cr O ~ It S- II~ 1 1 O '0 0 1 0 0 r C ~ t ~ C O +J

S O 1 I QJ CC O ~C O O

t E Ol 'I CL O

CI CL 5 cS

I crt CU I C)I S CA 0 0 ~ g U

iiI «C

CC ~C IA

0 0 0 0 0 0 0 0 Q 0 e 0 0 0 g 0 8 cc 0 g {da/da) JN3H9ld03VHd ) ' STAT IOII 0 STATION 3 I1 I t I \ l 1 0.7 t 0.7 I I C I I p 0,5 I 05 I I I I 0 I I ~C 0.3 P> 0.3 I CI /

CV B 0.1 0.1

C) M A M A N 0 F M A M J J A S 0 N 0 co J F J J S 0 CL LP o-e 1976 14 IO" < 5'TAT IO:I 1 o—o 1977 STAT 1.2 ~ Data not available 1.0 I \ 0.7 0,7 1 c I I 0.5 0.5 I I- I 0.3 0.3 C> Cf Ch 0.1 0.1 0 J F M A M J J A S 0 N 0 J F M A M J J A S 0 N 0

1.4 STATI011 2 14 STAT IOt( 5 1.2 1.2 I C I 1.0 1.0 J. I 0.7 I' 0.7 rh I I C I I 1 I 0.5 I 0.5 I II Ir 0.3 V 0.3 0.1 0.1

J F M A M J J A S 0 N 0 J F M A M J J A S 0 N 0

Figure D-25. Gross primary productivity at the St. Lucie Plant, March-December 1976 and January- December 1977.

D-54 l TABLE D-1

PHYTOPLANKTON SPECIES OCCURRENCE ST. LUCIE PLANT 1977

OBSERVED ONLY AT OFFSHORE STATIONS

Amphidini um Sp. 1 Grammatophora marina Cerati um buceros f. molle Ggmnodi ni um galesi anum Cerati um pulchell um Hemi aulus hauckii Cerati um trichoceros Hemiaulus sinensis Cerati um tripos Zsthmia enervis Chaetoceros laci ni osus Ni tzschi a filiformis Chaetoceros laevi s Prorocentrum redfi eldi Chaetoreros lorenzi anus Prorocentrum Spp. Chaetoceros vi stulae Rhi zosoleni a robusta Ch1orophyte spp. Scoliopleura Sp. Chrysophyte sp. 3 Sgnedra undulata Dactgli olsolen medi terraneus Trachelomonas Spp. Di plonei s di d @ma V. di dgma

OBSERVED MORE FREQUENTLY AT OFFSHORE STATIONS

Amphidini um SP. 2 Exuvi aella Spp. Apedinella radians Ggrodini um Sp. 1 Bacteri astrum deli catul um Hemidiscus cunei formis V. ventri cosa Cerati um fusus V. seta Lithodesmium undulatum Cerati um teres Peri dimi um depressum Cerati um Sp. 3 Peridini um hirobis Chaetoceros ei benii Prorocentrum mini mum Chaetoceros Spp., Pgrophacus horologi um Chlorophyte sp. 2 Rhizosolenia alata f. indica Chrysophyte sp. 2 Rhizosolenia calcar avis Climacodi um fra uenfel di anum Rhi zosoleni a cali ndrus Cgmatosira hei gi ca Rhi zosolenia i mbri cata Di ctgocha Spp. Rhizosolenia stolterfothii Eucampi a cornuta Synedra Sp. 1 Exuvi ael la bal tica

OBSERVED ONLY IN THE INTAKE/DISCHARGE CANALS

Amphora sp. 3 Ggrosi gma haiti curn V. bal ticum

D-55 I

I TABLE D-2

ANALYSIS OF VARIANCE FOR PHYTOPLANKTON DENSITY OFFSHORE STATIONS (0-5) ST. LUCIE PLANT JANUARY - DECEMBER 1977

egrees o Um 0 Mean Source freedom squares s uares

Months ll 1210657 x 10 t 10059 x 10„4. 43* Stations 5 22931 x 10 4586 x 10 1.84 Error 55 136474 x 10 2481 x 10 Total 71 1370062 x 10

0 T grees o Um 0 an Source freedom s uares squares

Months 11 1662227 x 108 151111 x 10 36.55* Stations 5 83671 x 10" 16734 x 10 4 04* Error 55 227374 x 108 4134 x 108 Total 71 1973273 x 108

~Significant at u = .05.

D-56

TABLE D- 3

ANALYSIS OF VARIANCE FOR PHYTOPLANKTON DENSITY OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

egrees o um o Mean Source freedom squares squares

Years (Y) 1 86601 x 10a 86601 x 108 15.44* ~on~hs (M) 9 1109651 x 123294 x 108 21.98* Stations (S) 5 x 10'9825108 17965 x 108 3.20* Y x M 9 649606 x lpa 72178 x 108 12.87* Y x S 5 30775 x 108 6155 x 10 1.10 M x S 45 286282 x 108 6361 x lps 1.13 Error 45 252335 x 108 5607 x 108 Total 119 2505077 x 10-

grees o Um 0 ean Source freedom s uares squares

Years (Y) 1 351786 x 10 351786 x 10 41. 21* Months (M) 9 22102)1 x 108 245579 x 1 pe 28.77* Stations (S) 5 222205 x lP8 44441 x 10 5.21* Y x M 9 1088551 x 10 120950 x 10 14.17* Y x S 5 15981 x lPS 3196 x 10 37.45* M x S 45 636495 x lps 14144 x 1.65 lps'534 Error 45 384072 x 108 x 108 Total 119 4909300 x lpa

*Significant at a = .05. January and February 1977 not included in analysis.

D-57 I l TABLE D-4

PEARSON CORRELATION COEFFICIENTS (r) FOR PHYTOPLANKTON DENSITY AND PIGNENTS VS. PHYSICAL AND CHEHICAL PARAHETERS, OFFSHORE SURFACE STATIONS (0-5) ST. LUCIE PLANT HARCH 1976 - DECENBER 1977

Phytoplankton Parameter Density Chloro h 11-a Phaeo i ment Chloro h 11-b Chl oroph 11-c Carotenoids

Temperature -.0653 .0315 -.0735 .0060 .0312 .0427 Terpe ra ture ~ -.0714 .0294 -.0716 .0131 .0286 .0394 (n-132)a Salinity -.1397 -. 1935* .0290 . 1187 -. 1524* -.2225* -.1403 -.1954* .0283 .1153 -.1547* -.2246* Salinity'n~132)

Dissolved Oxygen, .1073 .1277 -.0243 .0115 .1466* .0857 Dissolved Oxygen .1007 .1271 -.0248 .0064 1464* .0841 (n*l32)

Nitrate .0113 . 1265 -.0989 .0772 .1450 .1406 Ni tr .0137 .1334 -.1073 .0854 .1532 .1516 ate'n=56)

Nitrite, -.0400 -.0873 -.0599 .3017* -.0288 -.0347 Nitrite -.0525 -.0864 -.0798 . 2781* -.0296 -.0282 Asthenia'n=132)(n*l32)

Ammonia -.1075 -.1403 -.1331 .0715 -.1287 -.0958 -.0605 -.0905 -.1164 .0785 -.0696 -.0483

Phosphate -. 1201 -.1240 -.0335 .0582 -.1136 -.1142 Phosphate -.0982 -.0961 -.0252 .0701 -.0844 -.0864 (n*l02) Silica .0312 .0752 .0677 .4186* .1061 .1122 -.0120 .0350 .3754* .0186 .0208 Silica'n~66) I -.0596

'Significant at a * .05. a Number of observations. M W W W W W M

TABLE 0- 5

PEARSON CORRELATION COEFFICIENTS (r) FOR PHYTOPLANKTON DENSITY AND PIGHENTS VS. PHYSICAL AND CHEHICAL PARAHETERS, OFFSHORE BOTTOH STATIONS (0-5) ST. LUCIE PLANT HARCH 1976 - DECEHBER 1977

Phytoplankton Parameter Density Chloro h 11-a Phaeo i ment Chloro h ll-b Chloro h 11-c Carotenoids

Temperature .0050 .0287 -.0443 -.0526 -.0099 .0118 Temperature~ .0038 .0255 -.0429 -.0500 -.0118 .0074

'n*132)a

Salinity -.2883* -.2203* -. 3178* -.2477* -.2844* -. 3293* Salinity~ -.2882* -.2214* -.3158* -.2491 -.2852* -.3294* (n=l32)

Dissolved Oxygen .0653 .0476 -.0947 .0026 .0388 .0050 Dissolved .0598 .0408 -.0998 -.0071 .0307 -.0041

Oxygen'n~132)

C3 I Nitrate .1527 .2148 .2208 .2371* .2285* .2013 CJl Nitrate'n~54) -.0149 .0276 .0666 .0975 .0334 .0143

Nitrite -.0181 -.0199 -.0140 .1240 .0152 -.0027 Nitrite~ -.0464 -.0590 -.0353 .1192 -.0183 -.0276 (n*l32)

Anrenia .0130 .0589 -.0042 .0883 .0667 .0813 Aamoni .0441 .0312 a'n .0397 .0229 .0256 .0330 =132)

Phosphate . 3817~ .3149* 3871* .4023* . 3533* . 3436* Phosphate~ .4208* . 3611* .4266* .4180* .3940* .3908* (n= 102)

Silica .0508 .1683 .2040 .6080* .2271* .1966 Si 1 ica~ -.0131 .0921 .1486 .5833* .1547 .1191 (n~66)

'Significant at a ~ .05. a Number of observations. I I TABLE D- 6

MULTIPLE REGRESSION FOR OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Dependent Independent variables variablesa R

Density Temperature 0.294 0.086 Nitrite 0.357 0.128 Nitrite 0.494 0.244 Ammonia 0. 517 0.267 Active chlorophyll-a Temperature 0.324 0.105 Nitrite 0.412 0.170 Nitrite~ 0.565 0.320 Silica 0,. 588 0.346 Si1 i ca 0.653 0.426 Temper'ature~ 0.669 0.447 Nitrate 0.678 0.460 Nitrate~ 0.687 0.472

Phaeopigment Ammonia 0.434 0.188

Chlorophyll-b Silica 0. 521 0. 272 Temperature 0; 672 0.452 Silica~ 0;706 0.499 Ammonia 0'. 732 0.536 Ammonia~ 0.755 0.571 Sal inity 0.780 0 '09 Chlorophyll-c Temperature 0.320 0.102 Nitrite 0.424 0.180 Nitrite 0.575 0.330 Silica 0.612 0.375 Silica~ 0.675 0.455 Temperature 0.691 0.478 Carotenoid Temperature 0.307 0.094 Nitrite 0.402 0.162 Nitrite~ 0.549 0.301 Silica 0.578 0.335 Silica~ 0.641 0.411 Tem erature~ 0.655 0.430 a When the F-value to enter the regression was not significant (a=.05) for any independent variable, the stepwise procedure was stopped. D-60 TABLE D-7

COMPARISON OF INTAKE (STATION 11) AND DISCHARGE (STATION 12) PHYTOPLANKTON ST. LUCIE PLANT NOVEMBER 1976-DECEMBER 1977

emperature in nae >sc arge C anges sn ce count Date Intake Disc arge hT('C) cell s/1 iter) (eel 1 s/1 iter /

10 Nov 68.0 68.7 0.7 3,986,220.6 4,213,116.6 +5.6 (2o.'o) (2o.4) (o.4) 13 Dec 75.4 84.0 8.6 2,116,060.1 1,245,602.9 -41.1 (24. 1) (28.9) (4.8) 25 Jan 59.9 79.0 19.1 3,101,102.8 2,062,714.5 -33. 4 (15.5) (26.1) (lo.e) 15 Feb 69.8 90.1 20.3 1,051,416. 5 1,314,201 . 3 +24.9 (21.O) (32. 3) (11.5) ll Mar 70.5 93.9 23.4 657,321. 7 565,984.7 -13.8 (21.4) (34.4) (13.'o) 19 Apr 76.5 77.5 1.0 1,022,444. 4 1,512,525.8 +47. 9 (24.7) (25.3) (o.e) 10 May 75. 2 94.8 19.6 1,049,757.9 702,894. 2 -33. 0 (24.o) (34.9) (10.9) 14 Jun 81.1 100.9 19.8 1,293,545.6 339,202.3 -73.7 (27.3) (38.3)- (11.0) 12 Jul 76.8 97.7 20.9 1,062,604. 3 840,691.3 -20.8 (24.9)- (3e.5) (11.6) TABLE D- 7 (continued) COMPARISON OF INTAKE (STATION 11) AND DISCHARGE (STATION 12) PHYTOPLANKTON ST. LUCIE PLANT NOVEMBER 1976-DECEMBER 1977

empera ure in nae i sc arge C anges in ce count Date Intake Disc arge LT('C) (cells/li ter) - (ce»s/1 iter) ('A)

23 Aug 76. 6 99. 5 22.9 1,306,168.5 379,637. 7 -70.9 (24.8) (37.5) (12. 7) 13 Sep 84.0 107.6 23. 6 1,286,507.2 831,172.0 -35.4 (28.9) (42.0) (13.1) o 11 Oct 80.8 103. 1 22.3 1,466,091.0 1,755,461.3 -19.7 (27.1) (39. 5) (12.4) 2 Nov 75.6 95.9 20. 3 4,856,821.5 4,431,361.3 -8. 8 (24.2) (35.5) (».3)

1 Dec 75.4 98. 8 23. 4 2,664,0». 3 609,124. 4 -77.1 (24.1) (37.1) (13.0)

Average of surface and bottom readings. - Dischar e count Intake count x 100 Change in cell count = I l

I TABLE D-8

ANALYSIS OF VARIANCE FOR PHYTOPLANKTON DENSITY CANAL STATIONS (11, 12) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

JANUARY-DECE%ER 1977 grees o um o Mean Source freedom squares squares

Months ll 276268 x 25115 x 10s 9 99*

10'2481 Stations 1 x 10~ 12481 x 10s 4'96* Error ll 27664 x 10, 2515 x 10 Total 23 316412 x 10a

RCH 1976-DECEMBER 977 grees o um o Source freedom s uares squares

Years (Y) 1 207416 x 10a 207416 x 10s 56.88* Months (M) 9 473042 x 10" 52560 x 10a 14.41* Stations (S) 1 15942 x 10 15942 x 4.,37

10'8303 Y x M 9 254728 x 10'anloa x 10a 7. 76* Y x S 497 x 497 x 108 .14

10'8050 M x S 9 x 3117 x 10" .85 Error 9 x 10'281910s 3647 x 10a Total 39 1012494 x

*Significant at a = .05. January and February 1977 not included i n analysis.

D-63 TABLE D-9

PEARSGN CORRELATION COEFFICIENTS (r) FOR PHYTOPLANKTON DENSITY AND PIGMENTS VS PHYSICAL AND CHEHICAL PARAHETERS, CANAL STATIONS (il, 12) ST. LUCIE PLANT HARCH 1976 - DECEHBER 1977

Phytopl ankton Parameter Density Chloro h ll-a Phaeo i ment Chloro h ll-b Chloroph 11-c Carotenoids Terperature -. 2635* -.1293 .0545 .2439* -.0832 -. 1077 Temperature> -.2587* -.1456 .1018 .2425* -.0988 -.1233 (n=75)a

Salinity -. 1098 -. 3601* -.2404* -.2651* -.4231" -.4816* -. 1124 -. 3617" -.2296* -.2606* -.4233* -.4811 Salinity'n=74)

Dissol ved Oxygen .1142 .1870 -.1654 -. 3943* .1091 .0872 Dissolved . 1150 . 1759 -.1526 .3644* .1068 .0840 Oxygen'n*74)

Ni trate .4249* .5322* .0647 -.3476* .5318* .5344* Nitrate ~ . 3884* .5220* .0382 -. 3557* 5147* .5287* (n*27)

Nitrite . 3338* .1538 .0478 .0742 .1909 .1729 Nitrite .3659* .1914 .0266 .0648 . 2300* .2169* (n=75)

Ammonia .0028 .4056* -. 1624 .0352 . 3607* .3805* Ammonia .0224 .5962* -. 1178 -.0114 5410* .5627" (n=75)

Phosphate -.0609 -.0968 .5241* .2256* -.0911 -.0597 Phosphate -.0538 -.0822 .5172* .2053 -.0788 -.0444

'n=55)

Silica -.0649 .0130 . 3392* .6071* .0334 .0417 ~ 5 i 1 ica -.0902 -.0200 .2893 .5679* -.0011 .0129 (n~33)

*Significant at c ~ .05. He>her of observations. I I

I TABLE D-10

MULTIPLE REGRESSION FOR CANAL STATIONS (11, 12) ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Dependent Independent variables variablesa Density Phosphate 0.620 0.384 Silica~ 0.820 0.673 Ammonia~ 0.884 0.781 Ammonia 0.911 0.831 Silica 0.934 0.871 Temperature~ 0.952 0.907 Nitrite 0.966 0.933 Active chlorophyll-a Nitrate 0.531 0.282 Phosphate~ 0.704 0.496 Silica~ 0.771 0.595 Ammonia~ 0.822 0. 675 Ammonia 0.876 0. 767 Silica 0.898 0.807 Temperature~ 0.917 0.842

Phaeopigment Phosphate~ 0. 572 0. 327 Temperature 0.689 0.475 Temperature 0.757 0.573 Chlorophyll-b Silica 0.563 0.317 Chlorophyll-c Phosphate 0.538 0.289 Nitrate 0.751 0.564 Si 1 i ca~ 0.819 0.671

Carotenoid Ammonia~ 0. 537 0.288 Phosphate 0.694 0.482 Silica~ 0.819 0.670

Ammonia 0 F 887 0.786 Silica 0.905 0.820 Tem erature 0.923 0.852

a When the F-value to enter the regression was not significant (a=.05) for any independent variable, the stepwise procedure was stopped. ll

I I l

I I TABLE D- 1 l

ANALYSIS OF VARIANCE FOR CHLOROPHYLL-a AT OFFSHORE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Months 11 128.4400 11. 67636 72.78* Stations 5 2.9928 0.59856 3 73* Error 55 8.8227 0.16041 Total 71 140.2555

Bottom Months 11 257.4672 23.40610 49.25* Stations 5 8.5768 1.71536 3.61* Error 55 26.1387 0.47525 Total 71 292.1827

March 1976-December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Years (Y) 1 35.7188 35. 71880 71.07* Months (M) 9 195.9557 21.77286 43.32* Stations (S) 5 13.4511 2.69022 5.35* Y x M 9 123.1643 13.68492 27.23* Y x S 5 4.0380 0.80760 1.60 M x S 45 25.8410 0.57424" 1.14 Error 45 22.6169 0.50260 Total 119 420.7858

Bottom Years (Y) 1 28. 2169 28.21686 49.44* Months (M) 9 279.5283 31.05870 54.42* Stations (S) 5 19.6516 3.93031 6.89* Y x M 9 131.9219 14.65798 25.68* Y x S 5 2.0989 0.41978 0.74 M x S 45 65.3171 1.45149 2.54* Error 45 25.6812 0.57069 Total 119 552.4159

* Significant at a = .05. a January and February 1977 not included in analysis.

D-66 „ ~ I

I TABLE D-12

ANALYSIS OF VARIANCE FOR CHLOROPHYLL-a AND PHAEOPIGMENT AT INTAKE-DISCHARGE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean Pi ment Source freedom s uares s uares F Chloro- Months ll 49.13490 4.46681 5.10* phyll-a Stations 1 2.02711 2.02711 2.32 Error 11 9.62680 0.87516 Total 23 60.78879

Phaeo- Months 11 0.41352 0.03759 2.11 pigment Stations 1 0.03623 0.03623 2.04 Error ll 0.19563 0.01778 Total 23 0.64537

March 1976-December 1977 Degrees of Sum of Mean Pi ment Source freedom s uares s uares F

Chloro- Years (Y) 1 89.9846 89.98462 25. 10* phyll-a Months (M) 9 161.9741 17.99712 5.02* Stations (S) 1 17.2331 17.23305 4.81 Y x M 9 126.1967 14.02185 3.91* Y x S 1 2.2021 2.20214 0.61 1.05 M x S 9 33.8337 3.75930'.58463 Error 9 32.2617 Total 39 463.6860

Phaeo- Years (Y) 1 0.01541 0.01541 0.95 pigment Months (M) 9 0.32244 0.03583 2.21 Stations (S) 1 0.03813 0.03813 2.35 Y x M 9 0.31003 0.03445 2.12 Y x S 1 0.01024 ,0 '1024 0.63 M x S 9 0.11673 0.01297 0.80 Error 9 0 '4608 0.01623 Total 39 0. 95906

* Significant at a = .05. January and February 1977 not included in analysis.

D-67

TABLE D-l 3

ANALYSIS OF VARIANCE FOR PHAEOPIGMENT AT OFFSHORE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Months 11 0. 08794 0.00799 2. 26* Stations 5 0.03214 0.00643 1.81 Error 55 0.19474 0.00354 Total 71 0.31482 Bottom Months ll 0.71894 0.06536 3.49* Stations 5 0.23028 0.04606 2.46* Error 55 1.02792 0.01869 Total 71 1.97715

March 1976-December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Years (Y) 1 0.02640 0.02640 1. 53 Months (M) 9 0.33580 0.03731 2. 17* Stations (S) 5 0.30684 0.06137 3.57* Y x M 9 0.10387 0.01154 0.67 Y x S 5 0.09376 0.01875 1.09 M x S 45 0.72721 0.01616 0.94 Error 45 0.77348 0.01719 Total 119 2.36735

Bottom Years (Y) 1 2.78312 2.78312 24.12* Months (M) 9 5.24665 0.58296 5.05* Stations (S) 5 1.12802 0.22560 1.96 Y x M 9 3.21995 0.35777 3.10* Y x S 5 0.61625 0.12325 1.07 M x S 45 7.26692 0.16149 1.40 Error 45 5.19240 0.11539 Total 119 25.45328

* Significant at u = .05. a January and February 1977 not included in analysis.

D-68 TABLE D 14

ANALYSIS OF VARIANCE FOR CAROTENOIDS AT OFFSHORE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Months 11 107.4502 9.76820 62.47* Stations 5 3.3640 0.67279 4.30* Error 55 8.6006 0.15637 Total 71 119.4148

Bottom Months 11 250.3495 22.75903 39.12* Stations 5 11.7500 2.35000 4 04* Error 55 31,9971 0.5818 Total 71 294.0966

March 1976-December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Years (Y) 1 48. 4371 48.43713 102.29* Months (M) 9 167.6711 18.63011 39.34* Stations (S) 5 15.9192 3.18383 6.72* Y x M 9 99.2792 11.03103 23.30* Y x S 5 4.8208 0.96416 2.03 M x S 45 25.2213 0.56047 1.18 Err or 45 21.3079 0.47351 Total 119 382.6566

Bottom Years (Y) 1 71.5481 71.54811 55.07* Months (M) 9 295.7015 32.85571 25.28* Stations (S) 5 36.7774 7.35549 5.66* Y x M 9 137.9185 15.32428 11.79* Y x S 5 10.1189 2.02378 1.56 M x S 45 101.1911 2.24869 1.73 Error 45 58.4622 1.29916 Total 119 711.7177

* Significant at a = .05. a January and February 1977 not included in analysis.

D-69 I

I TABLE D-15

ANALYSIS OF VARIANCE FOR CHLOROPHYLL-c AT OFFSHORE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares F Surface Months ll 28.31495 2.57409 65.13* Stations 5 0.72674 0.14535 3.68* Error 55 2.17351 0.03952 Total 71 31. 21518

Bottom Months 11 56.04689 5.09517 5.91* Stations 5 1.88330 0.37666 4.13* Error 55 5.01201 0.09113 Total 71 62.94218

March 1976-December 1977a Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Years (Y) 1 8. 23715 8.23715 81.86* Months (M) 9 50.66145 5.62905 55.94* Stations (S) 5 2.50758 0.50152 4.98* Y x M 9 27.44795 3.04977 30.31* Y x S 5 0.78164 0.15633 1.55 M x S 45 4.71112 0.10469 1.04 Error 45 4.52789 '.10062 Total 119 98.87476

Bottom Years (Y) 1 11.63117 11.63117 57.38* Months (M) 9 68.82291 7.64699 37.73* Stations (S) 5 5.88142 1.17628 5.80* Y x M 9 28.52853 3.16984 15.63* Y.x S 5 1.86905 0.37381 1.84 MxS 45 13.27420 0.29498 1.45 Error 45 9.12053 0.20268 Total 119 139.12778

* Significant at a = .05. a January and February 1977 not included in analysis.

D-70 I

I I TABLE D-l6

ANALYSIS OF VARIANCE FOR CHLOROPHYLL-b AT OFFSHORE STATIONS ST. LUCIE PLANT MARCH 1976-DECEMBER 1977

Januar -December 1977 Degrees of Sum of Mean De th Source freedom s uares s uares

Surface Months 11 0.16367 0.01488 10.62* Stations 5 0.00557 0.00111 0.79 Error 55 0.07689 0.00140 Total 71 0. 24612

Bottom Months 11 0.30980 0.02816 15.64* Stations 5 0.00486 0.00097 0.54 Error 55 0.09922 0.00180 Total 71 0.41389

March 1976-December 1977a Degrees of Sum of Mean De th Source freedom s uares s uares F

Surface Years (Y) 1 0. 00105 0.00105 0.39 Months (M) 9 0. 32159 0.03573 13.13* Stations (S) 5 0.00561 0.00112 0.41 Y x M 9 0.05094 0.00566 2.08 Y x S 5 0.00729 0.00146 0.54 M x S 45 0.08811 0.00196 0.72 Error 45 0.12241 0.00272 Total 119 0.59699

Bottom Year s (Y) 1 0.15914 0.15914 13.85* ~on~hs (M) 9 0.51205 0:05689 4.95* Stations (S) 5 0.14467 0.02893 2.52* Y x M 9 0.22939 0.02549 2.22* Y x S 5 0.17920 0.03584 3.11* M x S 45 0 '1157 0.01137 0.99 Error 45 0.51705 0.01149 Total 119 2. 25305

* Significant at a = .05. a January and February 1977 not included in analysis. TABLE D- 17

ANALYSIS OF VARIANCE FOR GROSS PRIMARY. PRODUCTIVITY AT OFFSHORE STATIONS (0-5) ST. LUCIE PLANT JANUARY-DECEMBER 1977a

Degrees of Sum, of Mean Source freedom s uares s uares

Stations 5 0.09331 0. 01866 0.66 Months 6 0.44006 0.07334 2.61* Error 30 0.84268 0.02809 Total 41 1.37605

* Significant at a = .05. January, February, April, August and December were not included in analysis because data were not available at one or more stations.

D-72 I l E. ZOOPLANKTON

INTRODUCTION

The purpose of this study was to assess the effects of power plant operation on the density and composition of the zooplankton population. Variations in zooplankton density were analyzed and considered in relation to phytoplankton and the physical/chemical environment.

Zooplankton collectively refers to animals that are non-swimmers, poor swimmers, or free-floating organisms in a body of water. Zooplankters range in size from microscopic to macroscopic organisms variously distributed in the water column. Ecologically, zooplankton may be divided into two main groups: I) holoplankters, which spend their entire life cycles in the water column, and 2) mero- plankters, temporary members of the zooplankton that consist predom- I inantly of larval forms associated with benthic adults.

The availability of soluble nutrients, which promote phytoplankton growth and reproduction, determines the abundance of phytoplankton as a basic food source for subsequent grazing by zooplankton (Bain- bridge, 1953; Davis, 1955). Zooplankters, in turn, are an important food source for many other forms of marine animals.

E-1 I MATERIALS AND METHODS

Zooplankton was collected monthly at six offshore stations, 0 through 5 (Figure E-1). All except Station 0 were potentially subjected to thermal addition by heated water discharge from the plant discharge structure. Stations located in the intake and discharge canals (11 and 12, respectively) were sampled to determine immediate entrainment effects. Collections were made with a half-meter,

202'esh plankton net. Towing speeds were 0. 5 to 2 knots for intervals of 5 to 10 minutes. Duplicate samples were taken: one for qualitative and quantitative analysis and one for biomass determination.

Offshore samples were collected from surface and bottom depths by towing horizontally; intake samples were collected by step-oblique \ tows; and discharge samples were collected with a set net, since water velocity was sufficient to keep the net suspended and the water column was well-mixed due to the turbulence. Offshore, the water column ranged in depth from 7.1 to 11.2 meters. Surface samples were collected at sufficient depth (1 to 2 meters) to ensure continued submergence of the plankton net. A flowmeter positioned in the mouth of the net indicated the amount of water filtered. Weather conditions, tidal stage, and moon phase were recorded. Wind velocity (knots), current direction and velocity (cm/sec), air and water temperature ('C), salinity ('/~ ), dissolved oxygen (ppm), and turbidity were measured at each collection. Each sample was washed into a pre-labeled bottle and preserved with 5X buffered formalin, returned to the laboratory, and allowed to settle a minimum of four

E-.2 I

I I I days. Samples were concentrated by vacuum pump to a minimum work-

ing volume, and for qualitative and quantitative analysis, replicate

one-m9 aliquots were withdrawn with a Stempel pipette. Organisms were identified to the lowest practical taxon. Dissections and

staining were used when necessary for identification.

Zooplankters per cubic meter were calculated by multiplying the

count by appropriate dilution factors and dividing by the volume of water filtered in cubic meters. The volume of water filtered was cal cul ated by:

V = ~(rz)l

where: V = volume of filtered water r = radius of net at mouth

= 1 distance net is hauled.

Biomass of the zooplankton was determined by ash-free dry weight 'I (EPA, 1973). Results of these determinations were expressed as milli- grams of ash-free dry weight per unit volume of water.

Aliquots used as subsamples for identification and counts were

V retained along with the whole sample as vouchers., Vouchers were

retained as part of a permanent collection which may be used in the future to verify counts and identifications. Zooplankton data were analyzed by analysis of variance, and zooplankton density was related to oceanographic parameters through correlation and regression. '-3 ll ll

I RESULTS AND DISCUSSION

Zooplankton data for December 1976, which were not available for the 1976 annual report (ABI, 1977), are given in Appendix Tables N-I through N-3.

Members'f ten phyla observed during the January to December

1977 study period (Appendix Tables N-6 through N-27) were also observed during the 1976 study. They were Annelida (Polychaeta), Arthropoda (largely Crustacea), Bryozoa, Chaetognatha, Chordata,

Coelenterata, Echinodermata, Mol lusca, Nematoda, and Protozoa.

Rotifera were not found in the 1977 study; representatives of the

Phoronida were found in 1977. Copepods (Plate E-l), which are mostly holoplanktonic, were again the dominant component of the zooplankton and comprised 10 to" 94$ of the total population offshore. Other groups which were dominant at different times during 'the study included cirripedia (barnacle) nauplii, conchoe- cia elegans (an ostracod), echi noderm larvae, eggs, zvadne sp. and peni2ia sp. (cladocerans), foraminiferans (protozoa), molluscs (mostly gastropods), oikopleura sp. (an appendicularian), polychaetes, sagitta enslata and other chaetognaths.

As in the 1976 study, the zooplankton population was generally neri tie (nearshore) rather than oceanic (offshore) i n character. Oceanic zooplankters such as euphausids, salps including rhalia demo- cratica, siphonophores, and the chaetognaths pterosagitta draco,

E-4 I sagitta bipunctata, and s. serratodentata atlantica were found infrequently or in low concentrations. Neritic forms identified included

the chaetognaths s. friderici, s. helenae, and s. hispida; the polychaete, Tomopteris sp.; and the sergestid shrimp, Lucifer faxoni (Plate E-2). The dominant calanoid copepod was paracalanus aculeatus.

Other calanoids that occurred consistently throughout the year and are typically neritic included Acartia spinata, Labidocera aestiva, Temora turbinata, and vndinula vulgaris. Dominant cyclopoids included

Corycaeus (Corgcaeus) speciosus, C. (Onychocorgcaeus) latus, Farranula gracilis, and oncaea mediterranea. Euterpina sp., the dominant har- pacticoid copepod, occurred all year. All.of the species mentioned above are holoplanktonic.

Meroplanktonic forms made a major contribution to the zooplankton population and included the larvae of decapods, echinoderms, gastro- t pods, pelecypods, and polychaetes, along with actinotroch, actinula, cyphonautes and cypris larvae. Other meroplankton included barnacle nauplii, fish eggs, and stomatopod protozoeae.

Major physical, structural damage to individual zooplankters was noted in the microscopic analyses. Differeqces in the damaged and undamaged portions of the zooplankton populati'ons are represented in Figures E-2 through E-13. Zooplankton density was minimal in

December, when number s per cubic meter ranged from 16.7 to 1797.5

(Appendix Table N-4, Figures E-13 and E-14). Maximum zooplankton

E-5 I

I density occurred in March and ranged from 362.1 to 28,912.5 organisms per cubic meter (Figure E-4) ~

Biomass was minimal in January and ranged from 1.28 to 15.83 mg/ms

(Appendix Table N-5. Maximum biomass was found in July and ranged from 4.28 to 223.47 mg/ms. Minimum and maximum values represent seasonal pulses and may be expected to vary somewhat for density and biomass.

Canal Stations

The difference in temperature (aT) between the intake and

dis-'harge stations ranged from +0.1 to +13.1'C (Table E-1). The highest temperature of the 1977 study, 42.0'C, was recorded in the discharge canal in September.

Undama ed Zooplankton

There were no significant differences in densities of undamaged zooplankters between the intake and discharge stations for 1977 or I for the 'two years combined (Tables E-2 and E-3, Figure E-15). In addition,=there were no significant differences between years.

Dama ed Zoo lankton

Densities of damaged zooplankters (Table E-2) were significantly greater in the discharge than in the intake during 1977 (Table E-4, Figure E-15). This would i ndicate that zooplankters had suffered major structural damage as a result of passage through the plant. I

I There were no significant differences in the number of damaged zoo-

plankters between intake and discharge in 1976, when the plant was

not running or pumping minimally and with little or no thermal addition. Data for the canals for the two years combined (Table E-3)

indicated that the number of damaged zooplankters in the canals was

significantly greater in 1977 than in 1976 (Table E-4).

Biomass

Biomass showed no significant difference between the intake

and discharge in 1976 'owever, biomass was significantly greater 4 in the discharge in 1977 (Tables E-5 and E-6). Damaged zooplankters

were not differentiated from undamaged in biomass determinations and could thus account for the higher values. Higher biomass values in

the discharge may also be attributable to plant material, which was

visually observed in some samples, and/or cirripedia (barnacle)

nauplii populations, which frequently comprised 40 to 47K of the

total zooplankton population in the discharge canal. There was no significant difference between years for biomass values (Table E-7, Figure E-16).

E-7 I

I I I

I I I Offshore Stations

Ph sical arameters Physical parameters monitored during collections included temperature, salinity, and dissolved oxygen (Appendix Tables 0-1 through 0-3). Minimum temperatures were recorded in January and ranged from

16.3 to 18.5'C. Maximum temperatures occurred in June and July; mean temperatures were 27.8'C and 28.4'C, respectively. Zooplankton abundance correlated significantly with temperature and dissolved oxygen (Table E-8). Stepwise multiple regression indicated that these parameters combined accounted for a maximum 12Ã variation in the zooplankton population (Table E-9).

Undama ed Zoo lankton

Although there were no significant differences between stations (Table E-5), analysis of variance indicated significant seasonal variation in total zooplankton density between months in 1977 and between months in the two years combined (Table E-10). Significant positive correlations between temperature and zooplankton abundance at the offshore stations, surface and bottom (Table E-8), indicate that as temperature increases, so does zooplankton abundance. This positi ve relationship between the linear and curvi,linear functions of temperature and zooplankton density'robably reflects seasonal pulses of the zooplankton in warm months, since Tukey 's test for difference between means (Tables E-ll through E-12) indicated that zooplankton abundance was significantly greater in March and July (Figures E-4,

E-8 I

I E-8, and E-14) than in the other months. Total zooplankton densities in March 1977 ranged from 3323.2 to 28,912.5 zooplankters per cubic meter (Appendix Table N-8). Copepods comprised 70 to 93K of the total population. Densities in July 1977 ranged from 746.0 to 15,261.6 zooplankters per cubic meter (Appendix Table N-12). As in March, copepods made up the major portion of the population, 61 to 94K .

Biomass was also significantly greater in the month of March tha'n in the other months for the two years combined (Table E.-13). Zoo- plankton density and biomass were significantly greater in 1977 than in 1976 (Tables E-6, E-7, E-10, and E-12 ).

Differences in zooplankton abundance from month to month and year to year are normal seasonal variations. A number of seasonal

trends in the zooplankton noted in 1977 were, in general, also observed in 1976. Echinoderm larvae were abundant at offshore stations in the winter months. Sergestid protozoeae reached peak density in

December. penilia sp. was found in the warmer months, peaked in Octo-

ber, and began to decline in November and December. zvadne sp. also

occurred during the summer months, but peaked after senisia sp., in

November.

Brachyuran zoeae reached their highest concentrations in June,

July, and August, with some decline in the population in September,

and reached their minimum density in October, November, and December.

The meroplanktonic zoeae of two genera of coranercially important

E-9 I I I

I species were identified, callinectes sp. (brachyuran) and sicgonia sp. (penaeid); both reached maximum concentrations in August, al though densi ties were low (Appendix Table N-25) . The commercial fisheries for rock shrimp (sicyonia spp.) and blue crab (callinectes sapidus) in the St. Lucie Plant area are small and in St. Lucie County, Florida,. represent 1.45 and

Dama ed Zoo lankton

As was the case with undamaged zooplankters, there was no significant difference in damaged zooplankters between stations, but seasonal variation in damaged zooplankton density was significant between months in 1976, 1977, and the two years combined (Table E-14 ).

Tukey's test for difference between means (Tables E-15 and E-16 ) indicated that damaged zooplankton was significantly greater in August of 1976, mainly July in 1977, and July and August for the two years combined. Copepods represented the greatest percentage of damaged organisms in July 1977, ranging from 2 to 16Ã of the total zooplankton population.

De th variation Bottom zooplankton populations were greater than surface populations (Tables E-7, E-10, E-14, and E-17). Differences were significantly greater in 1976 for undamaged zooplankton densities and biomass and in 1977 for undamaged and damaged zooplankton densities. E-10 II

t For the two years combined, undamaged and damaged zooplankton and biomass were all significantly greater on the bottom. Since analysis of variance in 1977 did not indicate any significant density differences between stations, and also since bottom populations were greater than surface populations in 1976, differences between surface and bottom appear to be a natural phenomenon rather than a plant- related one. Many factors have been considered for this stratification in the zooplankton population. There was no trend between zooplankton density and inorganic nutrients or total organic carbon; nor was there any trend in correlations with phytoplankton density

(number/liter) or chlorophyll-a values, an indicator of phytoplankton bidmass. There was no apparent relationship with physical factors such as current (measured at the surface) and/or wind velocity, cloud cover, moon phase, or turbidity. Possible trophic interactions were also considered. The presence of either ctenophores and/or scypho- medusae such as Aurelia aurita, Chiropsalmus quadromanus, Stomolophis neleagris, and ramoya haplonema, which are known to be capable of. substantially reducing a zooplankton population by grazing, was noted by observation on the impingement screens. The occurrence of these planktivores did not noticeably affect the zooplankton density. Most of the copepods that occurred were filter feeders rather than carnivores and therefore would not have altered the zooplankton composi tion or density. Copepods did, however, show a tendency for greater densities on the bottom in June, July, and August when the water was calm. I During months when water conditions were choppy, the copepods tended to be more evenly distributed in the water column, although this was not consistently observed. If the natural tendency (without the influence of turbulent water) for the copepods is to congregate at the bottom, it is probably due to active light avoidance.

SUMMARY

The composition of the zooplankton population did not substantially change from 1976 to 1977. Essentially the same phyla were identified and copepods were the 'dominant component of the population.

This would i ndicate, so far as broad groups are concerned, that plant operation is not qualitatively altering the zooplankton population.

Analysis of variance indicated significant differences in zooplankton densities and biomass between months offshore. Tukey's test indicated that March and July densities and March biomass values were significantly greater than these values for other months.

Undamaged zooplankton densities and biomass were significantly greater in 1977 than in 1976. Seasonal fluctuations in zooplankton populations are normal occurrences and i ndicate no adverse effect due to plant operation offshore.

Analysis of variance and Tukey 's test i ndicated that abundance of damaged zooplankters in the discharge canal was significantly higher in 1977 than in 1976. This is a positive i ndication of the detrimental effect of plant operation on zooplankton. The zooplankton population was greater at the bottom than at the surface. Since this stratification was also noted in 1976, when there was little or no thermal addition offshore, it would appear to be a natural phenomenon.

E-13

LITERATURE CITED

ABI. 1977. Ecological monitoring at the Florida Power 8 Light Co. St. Lucie Plant, annual report 1976. Vol. 1. AB-44. Pre- pared by Applied Biology, Inc., for Florida Power 8 Light Co., Miami.

Bainbridge, R. 1953. Studies on the interrelationships of zooplankton and phytoplankton. J. Mar. Biol. Ass. U.K. 32:385-447.

Davis, C. C. 1955. The marine and fresh-water plankton. Michigan State University Press. 562 pp.

EPA. 1973. Biological field and laboratory methods for measuring the quality of surface waters and effluents. EPA-670/4-73- 001. U. S. Environmental Protection Agency. National Environ- mental Research Center, Cincinnati.

NOAA. 1977. Florida landings, annual summary 1975. National Oceanic and Atmospheric Administration. National Marine Fisheries Service. Current Fish. Stat. No. 6719. 11 pp.

E-14 I

I 80 "15 '

1 km

-N-

~ Q3

~ 'P

~ ' Q.

.v' I ~ I 04

"/,

~ ~ 27'20'—

FPL ST- LUC I E PLANT 'o

O O Qo p

Figure E-1. Locations of zooplankton sampling stations, 1977. I 80

EO IK El 80 n: 4

0 Stetlon 11 12 0 I 2 3 0 5 0 I 2 3 Loco t1 on INTARE OlscHARGL OFFSHORE OFFSHORE Oeoth 08LEQVE SVRFACE 8OTTOH

Q Va~gea QQ Oenege8

4 2OOO

I SC

1000

Stetlon ll 12 0 I 2 3 4 5 0 I 2 3 4 5 Locetlon INTARE 0!sCHARGE OffSHORE OFFSHORE Oeoth 08L I QVE SVRfACE 8OT'fOH Figure E-2. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, January 1977.

E-l6 I, 1 P I I

1 SO IJ CL',

Stat(on 'l1 I2 0 I 2 3 4 5 0 1 2 3 A 5 LOtatlan IHTARE DISCHARGE OFFSHORE Of F SHORE Dtoth teLIOVE SVRFACE BOTTOH

Q Vndaoa910 ~ Dana9RO

5000

cc 4000

0 H 3000

Station N 12 0 I 2 3 ~ 5 0 1 2 3 o 5 latatlan !HIVE DISCHARGE OffSHORE OffSHORT Dtotn ORL IOVE SVaf ACE DOTTOH Figure E-3. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, February 1977.

4l fD e

~'oI

Stntlon II I2 0 I 2 3 6 5 0 I 2 3 n 5 Loentlon INTAKE DISCIIARGE OFFSNORE DFFSNORE Depth OBL I OVE SVPFACE BDTTOH

p Vnoeewled

~ TOOO MI n; 6000 u SOO ne

~ n n C> ~4

Cb Stetlon ll 12 0 I 2 3 0 I 2 3 n 5 Loeetlon INTAKE DISCHARGE OF FSNORE OFFSHORE Depth OBL lOVE SVRFACE BDTTON Figure E-4. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, March 1977. l 14

I 40

StotIon 11 12 0 I 2 3 4 8 0 I 2 3 4 5 LOCRtlOn INTAKE OISCHARGE OfFSHORE OFFSHORE Oeoth OGL IOVE SVRFACE 8OTTCII

Q Vnee~oed ~ Oenf fed

~~ 4000

Stetton 11 12 0 I 2 3 4 5 0 I 2 3 4 S Locetion INTAKE OISCHARGE OffSHORE OfF SHORE Oenth 08LIOVE SVRFACE 801103

Figure E-5. Undamaged zoop 1 ankton dens ity and re 1 ati ve percentages of damaged and undamaged zoopl ankters , St . Luc i e Plant , April 1977 . I I

Station 11 1 2 0 1 2 3 5 0 I 2 3 a 5 LOCat1 On INTAKE OISCHARCE OFFSHORE OFFSHORE Oaf th OSL IQVE. SVRFACE SOTTOH

Q Vndanaaad Q OanaOaO ~C I W

EP Cl El aa ~ 3000

O «j

Station 0 1 2 3 a 5 0 1 2 3 a 5 LOCatlan IHTARE OISCHARGE OFFSHORE OffSHORE Oaoth OSLIOVE, SVRFACE 5OTTOH Figure E-6. Undamaged zoopl ankton density and rel ati ve percentag es of damaged and undamaged zoopl an kters , St . Luci e Plant , May 1977 .

E-20 I 4Iu I unc CL

0 Stetfon ll, 12 0 'I 2 3 d 5 0, I 2 3 d 5 totetfon INTAKE DISCHAROE OFFSHORE OFfSHORE Depth DOE IOOE SORFAEE OOTT(pt

p Vndene9ed Dene9ed u 6000 I n D u ~Cl u 5000 ~C 0

I ~4000u

C C> IV

0 Stetl0 n 11 12 0 1 2 3 d 5 0 I 2 3 4 5 Loco tton IHTAKE DISEHARCE OfFSHORE OfFSHORE Depth ORE IDOE SURFACE OOTTOH Figure E-7. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, June 1977. "Ag q ~ I

t, I

I 4 t 4 r

~ f 4 I

I 60 El CC n

40 I

0 , StetlOn 11 12 0 I 2 3 4 0 I 2 3 Lotetton ENTARE DESCHARGE OffSHORE OffSHORE Depth OBLIOUE SURfACE BO110H

Q Undene9ed D~ Dent 9ed

GOOD OC n

4000 tlCl

0 Stett n 11 12 0 1 2 3 n S 0 1 2 3 ~ S Lotetton INTAKE DISCHARGE OffSHORE OffSRORE Booth OBLlOUE SURfACE BO)fON

Figure E-8. Undamaged zooplankton dens ity and re 1 ati ve per cen tages of damaged and undamaged zoo- p 1 ankters , St . Luci e P 1 ant , July 197 7 .

E-22 1 I R BO n

Stot ton 12 0 I 2 3 4 5 0 'I 2 3 n 5 Loco tton INTAKE OISCHARGE OFFSHORE OFFSHORK Oopth OBLIGE SVRFACE BOTION o

Q Item.~9g 5000 Q Oono9od I o El CO v 5000 OC

Vl 4f 4I 4000

MC>

0 4 Stot ton 11 '12 0 I 2 3 4 5 0 I 2 3 5 LOCOtIOn INTARE OISCHARGK OFFSET)RE OFFSHORE Oop\h OBL IOOE StiPFACE BOUN Figure E-9. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, August 1977.

E-23 I

I 80

I 60 4C

Stotton 12 0 1 2 3 4 5 0 I 2 3 4 5 Loeotlon INTAKE DISCHARGE OfISHORE OffSHORE Depth ODLIOVE SVRfACE DOT TON

Q vw~geo Q IH~g~ ~

OC I " noo0 4J ED 4J ne o 3 Vl ce

C C> ~V

Stetlon 'll 12 0 I 2 3 4 5 0 I 2 3 4 5 OffSHORE OEESHORE Loeetlon INTAKE DISCHARGE " Depth OBL IOVE 'SVPIACE eOTTOH Figure E-10. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, September 1977. I

I I

I 4J

~ 60

Stetlon ll 12 0 I 2 3 4 5 0 I 2 3 4 5 Loco tlon INTAKE OISCHARCE OFfSHORE OFFSHORE Depth 08I.IOVE SORF ACE 8OTTON

Q Ihnleeeoed Deneeee "3OOO ~ M

~L' 2000 Vl OC W

e NNO 'Do M

0 Stetl On Il 12 0 I 2 3 o 5 0 I 2 3 4 5 Locetlon INTAKE OISCHARSE OfFSHORE OffSHORE Depth 08L I QOE SURFACE 80TTOH Figure E-ll. Undamaged zoopl an kton density and relative percentages of damaged and undamaged zoo- p 1 an kters , St . Luci e P 1 ant , October 1 977 .

E-25 I u 80

12 Stotlon II 0 I 2 3 4 5 ~ 0 I 2 3 4 5 LOCOtlen INTAKE OISCHARGE OffSHORC OffSHORC VOLI OVE Oopth SVRTACE 80TTOH

Q VndontStd Q Oonf9od

ec 5000

X u ~S u 4

~V 3000

co IV

Stotton 11 12 0 1 2 3 4 5 0 I 2 3 n 5 Loootfon INTAKE OISCHAROE SHORE Off Off SHORE Oooth VOLI OVC SVRTACE 80TTOH Figure E-12. Undamaged zooplankton density and relative percentages of damaged and undamaged zooplankters, St. Lucie Plant, November 1977.

E-26 I

I I 90

Stetion ll I2 0 I 2 3 d S 0 I 2 3 4 S Locetlon INTAKE olscHARCE OFFSHORE OFFSHORE Oeoth OSL I OVE SURFACE SOTTOH

Vndene9ed w 2000 Q Q Delhloed

Vl CC

1C 280 CL Stot ton 0 'I 2 3 d 5 0 I 2 3,o S C> 'O Lotet ton INTAKE DISCHARCE OFFSHORE OFFSHORE Depth OSLIOVE SVRFACE DOTTOH

Figure E- 13 . Undamaged zoopl ankton dens ity and r el ati ve percentages of damaged and undamaged zoopl a nkters , St . Luci e Plant , December 1 977 .

E-27 II

4 „l

I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Station ll ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ "~ Station 12 Station 0 Station 1 Station 2 Station 3 —————-Station 4 12600 Station 5

11200

Cgi

Q 9800

g 1 g I I g hC I g 7000 I

C) g I CO M g g g I

1 g I I g I g 1 I g g Ig

I I I I II II II lg ~ II ~ I ~ ~ ~ ~ ~

~ \ \ ' ri ~ ~ ~ stsg~ ~ ~ ~~ ~ ~ ~ , 0 ~ ~ ~ ~ 0 0 ~ ~ 0 ~ ~ 40 ~ ~ ~ 4g ~ ~ ~ I P gg

JAi FEB NR APR rAY JW JUL AUG SEP OCT ROY DEC JAN FEB NR APR NY JUgi JUL AUG SEP OCT BOY DEC JA.i FEB NR APR NY JW JUL AUG SEP OCT BOY DEC 1977 1977 1977

Figure E-14. Mean zooplankters per cubic meter by date and station, St. Lucie Plant, January-December 1977.

E-28 A

%% ~ ~ g ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ % K o IOO

ICO

tCO

4 Itltilt II 12 2 C 5 tetltllO ICICKC CCICttCCCC OfSSIOCC CffIMWC tootc COCICCC CttfCCK COII(tt

g IIIC o 2440 llrr ~J P o

4 Stotto l2 0 I 2 o 2 tilttllO I'ltltt 415COCCCI Off Iffft CfIttfat Ctotl CCINLC ItofCCC

Chllll'igure E-15. Annual mean densities of undamaged and damaged zooplankton, St. Lucie Plant, 1976 and 1977. I I

I I I

I g ISIS II11

K tt

Stall~ Il It 2 ISHtlQC IICa SION I%SAIS OISCNIKC IIIISHNf Ilf CeOIh OIII'l4 QRfAX SOII\N Figure E-16. Annual mean zooplankton biomass values, St. Lucie Plant, 1976 and 1977. I

I I I

I I I I TABLE E-1

SUMMARY OF ZOOPLANKTON COUNTS, ZOOPLANKTON PHYSICAL CONDITION, AND INTAKE AND DISCHARGE TEMPERATURES ST. LUCIE PLANT JANUARY-DECEMBER 1977

arame ters em erature Number per cubic meter X Total o ulation dama ed nta e Disc arge Date nta e Disc ar e Inta e Disc arge ~ (ambient) therma 1 ) AT ' 25 JAN 105. 5 197. 5 2 15.5 26.1 +10. 6 15 FEB 567.5 459.1 3 5 21. 0 32. 3 +11. 3

11 .MAR 680. 9 362.1 3 4 21.4 34.4 +13.0 20 APR 237. 6 351.9 2 5 24. 8 24.9 '0.1 10 MAY 310. 4 349.2 2 7 24.0 34. 6 +10. 6 14 JUN 967. 4 288. 3 3 18 27. 3 38. 3 +11.1 12 JUL 948. 8 1042.6 3 9 24. 9 36. 5 +11. 6 23 AUG 964. 8 607.6 4 14 24. 8 37. 5 +12:7

13 SEP 963. 1 1228. 3 3 11 28.9 42.0 +13.1

11 OCT 3331. 2 2408.1 2 2 27. 1 39.5 +12.4

2 NOV 1862.7 1630.5 1 3 24.2 35. 5 +11. 3

1 DEC 363. 2 319.8 2 3 24.1 37.1 +13. 0

Values expressed are undamaged zooplankters and represent the mean of three subsamples. I

I TABLE E- 2

ANALYSIS OF VARIANCE FOR ZOOPLANKTON DENSITIES (No./m3) INTAKE AND DISCHARGE .STATIONS ST. LUCIE PLANT JANUARY-DECEMBER 1977

Un amage egrees of um o ean Source freedom S uares Square F

Month ll 1312610 x 10 1193282 19. 31* Station 1 17621 x 10 176208 2.85 Error ll 67962 x 10 61783 Total 23 1398193 x 10

Dama ed egrees o um 0 ean Source freedom S uares Square

Month ll 1746839 x 10 1588035 x 10 3 1.976 2 3 Station 1 446354 x 10 4463539 x 10 5.554* Error ll 884027 x 10 2 803661 x 10 3 Total 23 3077220 x 10

*Significant at a = .05.

E-32 TABLE E-3

ANALYSIS OF YARIANCE FOR ZOOPLANKTON DENSITIES (No./m3) INTAKE AND DISCHARGE STATIONS ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

Undama ed egrees of Um 0 ean Source freedom S uares Square

Year (Y) 1 190051 x 10~ 4385348 x 10 2.95 Month (M) 9 1561384 x 10 173487 x 10 2.70 Station (S) 1 85304 x 102 85304 x 10 1.33 Y x M 9 1192182 x 10~ 132465 x 10 2.06 Y x S 1 51752 x 10 51752 x 10~ 0.805 M x S 9 535739 x 102 59526 x 10 0.925 Error 9 578885 x 102 64321 x 10 Total 39 4195297 x 10

Dama ed egrees o um 0 ean Source freedom Squares Square

~ s Year 1 857803 x 10 8578028 x 10 11.11* (Y) ~ Month 9 1010664 x 10 1122960 x 10 1.45 (M) 3 1 3010790 x 10 3.90 Station (S) 2 3 Y x M 9 657446 x 10 730495 x 10 0.946 ~ Y x S 1 200365 x 10 2003648 x 10 2.59 2 3 M x S 9 342877 x 10 380974 x 10 0.493 2 Error 9 695189 x 10 772432 x'10 Total 39 4065423 x 10 2

Analysis did not include January and February 1977. *Significant at a = .05.

E-33 TABLE E-4

DIFFERENCES BETWEEN MEAN ZOOPLANKTON DENSITIES (No./ms) DAMAGED ZOOPLANKTERS, INTAKE AND DISCHARGE STATIONS ST. LUCIE PLANT

STATION COMPARISON - JANUARY-DECEMBER 1977

Intake Discharge Di fference

22.8 50.1 27.3*

YEAR COMPARISON - MARCH 1976-DECEMBER 1977

1976 1977 Difference 12.0 41.3 29.3*

a Analysis includes March, Hay, June, October, and November, 1976 and 1977. *Significant at a = .05. I TABLE E-5

ANALYSIS OF VARIANCE FOR ZOOPLANKTON BIOMASS (mg/m ) ST. LUCIE PLANT JANUARY-DECEMBER 1977

Intake and Dischar e Stations egrees of um of ean Source freedom S uares Square

Month ll 143. 2833 13.02576 — 3.72* Station 1 80. 3366 80.33655 22.9* Error ll 38. 4746 3.49769 Total 23 262.0945

Offshore Stations egrees o um 0 ean Source freedom Squares Square

Month (M) 9 20148.17 2238.686 1.73 Station (S) 5 7532.92 1506.584 1.16 Depth (D) 1 3978.60 3978.603 3.08 M x S 45 54166. 39 1203.698 0.93 M x 0 9 5079. 31 564.368 0.43 S x D 5 6112. 52 1222.505 0.96 Error 45 58199.38 1293.319 Total 119 155217.29

*Signi ficant at a = . 05.

E-35 I

I TABLE E-6

DIFFERENCES BETWEEN MEAN ZOOPLANKTON BIOMASS (mg/m ) ST. LUCIE PLANT

STATION COMPARISON - INTAKE AND DISCHARGE STATIONS, JANUARY-DECEMBER

1977'ntake Discharge Difference 2.8 6.5 3.7*

YEAR COMPARISON — OFFSHORE STATIONS, 1976-1977

1976 1977 Difference 13. 2 24.0 10.8*

DEPTH COMPARISON - OFFSHORE STATIONS, 1976-1977

Surface Bottom Difference 11.8 25. 3 13.5*

Analysis includes March, May, June, October, and November, 1976 and 1977. *Significant at c = .05.

TABLE E-7

ANALYSIS OF VARIANCE FOR ZOOPLANKTON BIOMASS (mg/m ) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

n a e and Dischar e Stations egrees of um o ean Source freedom S uares Square

Year (Y) 1 13.1890 13.18897 0.047 Month (M) 8 387.8169 48.47711 1.92 Station (S) 1 9.4557 9.45565 0. 37 Y x M 8 437.6901 54.71126 2 .,1 7 Y x S 1 43.4940 43.49394 1 . 72 M x S 8 235.7218 29.46521 1 . 1 7 Error 8 169.2625 21.15781

Total 35 1296.6300 .

Offshore Stations egrees o um 0 ean Source freedom Squares Square

Year (Y) 1 3494.14 3494.143 8. 35* Month (M) 4 16272.06 4068.014 9. 73* Station (S) 5 8223.22 1644.644 3.98* Depth (D) 1 5470.92 5470.922 13.08* Y x M 4 4289.58 1072.394 2.56 Y x S 5 3707.31. 741 .463 1.77 Y x D 1 723.70 723.699 1.73 M x S 20 48668.23 2433.412 5.82* M x D 1745.07 436.268 1.02 S x D 5 11528.24 2305.647 5.51* Y x M x S 20 10113.11 505.655 1.21 Y x M x D 4 1408.60 352.150 0.84 YxSxD 5 3460.86 692.172 1.66 MxSxD 20 51655.99 2582.799 6.18* Error 20 8361. 31 418.065 Total 119 179122.06

Analysis includes March, May-December, 1976 and 1977. Analysis includes March, May, June, October, and November, 1976 and 1977. *Significant at a = .05. E-37 TABLE E-8

SIMPLE CORRELATION COEFFICIENTS (r) FOR ZOOPLANKTON ABUNDANCE AND BIOMASS VS. PHYSICAL PARAMETERS OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

S RFACE BOTT M Physical Biomass Un amage amage Biomass Undamaged Damage arameter (mg/m ) (No./ms) (No./ms) m /ms) No./m ) No./ms)

Temperature 0.1836* 0.1767* 0.2400* 0.0872 0.1787* 0.2886* Temperature~ p.1948* 0.1833* 0.2461* 0.0891 0.1958* 0.2808*

Salinity 0.0628 0.0408 -0.1220 -0.0285 0.0786 -0.0082 Sal ini ty~ 0.0624 0.0393 -0.1231 -0.0282 0.0778 -0.0104

Dissol ved oxygen -0.1567* -0.0759 -0.2097* -0.0440 -0.1710* -0.2283* Dissolved oxygen~ -0.1377 -0.0551 -0.1930* -0.0325 -0.1293 -0.1988* l TABLE E- 9

MULTIPLE REGRESSION ANALYSIS OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

Depen ent In ependent variables variables

Undamaged density Temperature~ 0.18326 0.03358 Salinity 0.19697 0.03880 Temperature 0.20406 0.04164 Dissolved oxygen 0.20567 0.04230 Dissolved oxygen~ 0.32176 0.10353

Damaged density Temperature~ 0.24606 0.06055 Dissolved oxygen 0.27594 0.07614 Dissolved o>magen~ 0.33490 0.11216 Salinity 0.34980 0.12236

Bi omass Temperature~ 0.19481 0.03795 Temperature 0.23104 0.05338 Dissolved oxygen 0.24806 0.06153 Dissolved oxygen 0.31854 0.10147 Salinity 0.32556 0.10599

Depen en n epen ent variables vari ab1 es R

Undamaged density Temperature 0.19098 0.03647 Temperature 0.23912 0.05718 Dissolved oxygen 0.26083 0.06803 Dissolved oxygen 0.27852 0.07757 Sal inity 0.28560 0.08157

Damaged density Temperature~ 0.26027 0.06774 Dissolved oxygen 0.29218 0.08537 Dissolved oxygen 0.32457 0.10535 Sa 1 inity~ 0.32783 0.10747 Temperature 0.32834 0.10781

Biomass Temperature 0.08720 0.00760 Sal inity 0.08884 0.00789 Temperature 0.08929 0.00797

E-39 TABLE E-10

ANALYSIS OF'VARIANCE FOR ZOOPLANKTON DENSITIES (No./m3) UNDAMAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT

anuar y- ecem er 7 egrees of ulll 0 ean Source freedom S uares Square

Month (M) ll 4913657 x 10 4466960 x 10 4.29* Station (S) 5 4678502 x 10 9357003 0.90 Depth (D) 1 7086271 x 10 7086270 x 10 6.81* M x S 55 4533187 x 10 8242158 0.79 M x 0 ll 1118091 x 10 1016446 x 10 0.98 S x D 5 3589220 x lOz 7178439 0.69 Error 55 5722304 x 10 1040419 x 10 Total 143 1782264 x 10

Mare 76- ecem er egrees o Ulll 0 ean Source freedom Squares Square

10~ 57* Year (Y) 1 ,1447572 x 10 1447572 x 18. Month (M) 7 3146341 x 10~ 4494771 x 101 5 77* Station (S) 5 5491369 x 10 1098274 x 10'.41 102 11* Depth (D) 1 1177965 x 10 1177965 x 15. 10> Y x M 7 1548944 x 10 2212776 x 2.84* Y x.S 5 2414415 x 4828830 0.62

10'248683 YxD 1 6248683 ) 0.80 MxS 35 2562377 x 10 7321078 0.94 MxD 7 5639042 x 8055773 1.03 SxD 5 x 10'660252 5320503 0.68 YxMxS 35 x 1010'393227 9694933 1.24 YxMxD 7 5109795 x 7299707 0.94 YxSxD 5 x 10'274066 1254813 x 10'.61 MxSxD 35 x 10'94731310~ 1127804 x 10'.45 Error 35 2728689 x 10~ 7796253 Total 191 2277381 x 103

Analysis includes March-August, October, and November, 1976 and 1977. *Significant at a = .05.

E-40 I

I s TABLE E-ll

DIFFERENCES BETWEEN MONTHLY MEAN ZOOPLANKTON DENSITIES (No./ms) UNDAMAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT JANUARY-DECEMBER 1977

ont FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC (Mean) (3675.5) (7160.2) (2730.1) (2289.2) (2923.6) (6867.6) (3727.0) (3194.0) (1731.9) (3383.9) (742.3)

JAN (1715.3) 1960.2 5444.9* 1014.8 573.9 1208. 3 5152. 3* 2011. 7 1478. 7 16.6 1668.6 973.0 FEB (3675.5) 3484. 7 945.4 1386. 3 751.9 319.2.1 51.5 481. 5 1943. 6 291.6 2933. 2 MAR (7160.2) 4430.1 4871.0* 4236.6 292.6 -3433.2 3966.2 5428.3* 3776.3 6417.9* APR (2730.1) 440.9 193. 5 41 37. 5 996. 9 463. 9 998. 2 653. 8 1987. 8 MAY (2289.2) 634.4 4578.4* 1437. 8 904.8 557. 3 1094. 7 1546. 9 JUN (2923.6) 3944.0 803.4 270.4 1191.7 460.3 2181.3 JUL (6867.6) 3140.6 3673.6 5135.7* 3483.7 6125.3* AUG (3727.0) 533.0 1995.1 343.1 2984.7 SEP (3194.0) 1462;1 189.9 2451.7 OCT (1731.9) 1652.0 989.6 NOV (3383.9) 2641.6

*Significant at a = .05, Tukey's HSD = 4497. I TABLE E- 12

DIFFERENCES BETWEEN MEAN ZOOPLANKTON DENSITIES (No./m ) UMDAMAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

977 erence 2115.1 3851. 7 1736.6*

Month y ont UN .T (Mean) 2152.1 1384.3 2166.4 (5067.3 4026.8 1813.2 2744.9

MAR (4512.0) 2359.9 3127.7* 2345.6 555. 3 485.2 2698.8* 1767.1 APR (2152.1) 767.8 14.3 2915.2* 1874.7 338.9 592.8 MAY (1384. 3) 782.1 3683.0* 2642.5* 428.9 1 360.6 JUN (2166.4) 2900.9* 1860.4 353.2 578.5 JUL (5067.3) 1040.5 3254.1* 2322.4 AUG (4026.8) 2213.6 1281.9 OCT (1813.2) 931.7

Analysis includes March-August, October, and November, 1976 and 1977.

*Significant at a = .05, Tukey's HSD = 2599.

TABLE E-13

DIFFERENCES BETWEEN MONTHLY MEAN ZOOPLANKTON BIOMASS (mg/ms) OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 - DECEMBER 1977

Flont JUN N (Mean) (14.8) 14.9 10.3) (11.3)

MAR (41.6) 26.8* 26.7* . 31.3* 30 3*

MAY (14.8) 1.0 4.5 3.5

JUN (14.9) 4.6 3.6

OCT (10. 3) 1.0

Analysis includes March, May, June, October, and November, 1976 and 1977. *Significant at a = .05, Tukey's HSD = 17.65. I TABLE E-14

ANALYSIS OF VARIANCE FOR ZOOPLANKTON DENSITIES (No./m3) DAMAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT

anuary- ecem er 7 egrees of Ulll 0 ean Source freedom S uares Square

Month (M) ll 1146225 1042023 x 10 5.02* i Station (S) 5 1563108 x 10 i 3126216 x 10 i 1.51 Depth (D) 1 1750422 x 10 1750421 x 10 8.43* ~ M S 1973119 x 10 0.95 x 55 1085215 i M x D ll 3186992 x 10 2897265 x 10 1.40 S x D 5 6166812 x 10 1233362 x 10 0.59 Error 55 1141838 2076069 x 10"~ Total 143 4084998

Mare 976- ecem er egrees o um o ean Source freedom Squares Square i Year (Y) 1 4211548 x 10 4211548 x 10 19.90* Month (M) 7 1577242 2253203 x 10 10.65* 2 Station (S) 5 1302098 x 10 2604196 x 10 1.23 Depth (D) 1 1744958 x 10 1744958 x 10 8.25* Y x M 7 x 10 '521925 1074561 x 10 5.08*

i '416227 Y x S 5 2208114 x 10 x 10 2.09 ~ Y x D 1 4391729 x 10 4391729 x 10 2.08 M x S 35 1400134 4000382 x 10 1.89* 2 M x D 7 1875611 x 10 i 2679444 x 10 1.27 S x D 5 1587400 x 10 3174800 x 10 1.50 Y x M x S 35 1098996 3139989 x 10 1.48 i 2 Y x M x D 7 1525898 x 10 2179855 x 10 1.03 2 Y x S x D 5 7803405 x 10 1560681 x 10 0. 74 M x S x D 35 1062547 3035849 x 10 1.43 Error 35 7406280 x 10 i 2116080 x 10 ~ Total 191 8199254

Analysis includes March-August, October, and November, 1976 and 1977. *Significant at a = .05.

E-44

TABLE E-15

DIFFERENCES BETWEEN MONTHLY MEAN ZOOPLANKTON DENSITIES (No./m ) DAHAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT JANUARY-DECEMBER 1977

. ont ARP MAY JUN JUL AUG SEP OCT NOV DEC (Mean) 79. 2 259.1 193.5 (128.4 (144.7) (365.3 (258. 3) (131 . 5) (162.2) (106.9) (50. 7)

JAN (62.5) 16. 7 196. 6 131.0 65.9 82.2 302.8* 195.8 69.0 99.7 44.4 11.8 FEB (79.2) 179.9 114.3 49.2 65.5 286.1* 179.1 52.3 83.0 27.7 28.5 MAR (259.1) 65.6 130.7 114.4 106.2 0.8 127.6 96.9 152.2 208.4* APR (193.5) 65.1 48.8 171.8 64.8 62.0 31.3 86.6 142.8 MAY (128.4) 16.3 236.9* 129.9 3.1 33.8 21.5 77.7 JUN (144. 7 ) 220.6* 113.6 13.2 17.5 37.8 94.0 JUL (365.3) 107.0 233.8* 203:1* 258.4* 314.6* AUG (258.3) 126.8 96.1 151-.4 207.6* SEP (131. 5) 30.7 24.6 80.8 OCT (162. 2) 55.3 111.5 NOV (106.9) 56.2

*Significant at a = .05, Tukey's HSD = 201.

M W & & & & & W

TABLE E- 16

DIFFERENCES BETWEEN MONTHLY MEAN ZOOPLANKTON DENSITIES (No./ms) DAMAGED ZOOPLANKTERS, OFFSHORE STATIONS (0-5) ST. LUCIE PLANT MARCH 1976 — DECEMBER 1977

ont APR MAY JUN JUL AUG OCT (flean) (118.2 82.7 (82.0 225.0) 355.3 (114.8) (77.1

MAR F (188,6) 70.4 105.9 106.6 36.4 166.7* 73.8 111.5

APR (118.2) 35. 5 36. 2 106.8 237.1* 3.4 41.1

MAY (82.7) 0.7 142.3* 272.6* 32.1 5.6

JUN (82.0) 143.0* 273.3* 32.8 4.9

JUL (225.0) 130. 3 110.2 147. 9*

AUG (355.3) 240.5* 278.2*

OCT (114.8) 37.7

Analysis includes March-August, October, and November, 1976 and 1977. *Significant at a = .05, Tukey's HSD = 135.4. TABLE E-17

DIFFERENCES BETWEEN SURFACE AND BOTTOM MEAN ZOOPLANKTON DENSITIES (No./ms) OFFSHORE STATIONS (0-5) ST. LUCIE PLANT

Undama e zoo an ters Date Sur ace Bottom erence January - December 1977 2643.5 4046.5 1403.0*

March 1976 - December 1977 2200.1 3766.7 1566.6*

ama e zoo an ters ate Surface Bottom s ference January - December 1977 127.0 196.7 69. 7* March 1976 - December 1977 125.3 185.6 60.3*

Analysis includes March-August, October, and November, 1976 and 1977.

*Significant at a = .05. Plate 1. Copepods (scanning electron micrograph). I I

C ~ I I

I Plate 2. Lucifer faxoni (scanning electron micrograph). I

I I P. AIIAAATTIICCINCACPATTTT

INTRODUCTION

The offshore aquatic benthic macrophytes were sampled to determine if the operation of the St. Lucie Plant was affecting this community. The. term "aquatic macrophytes" refers to aquatic plants large enough to be seen with the unaided eye. In the marine environment this includes the seaweeds and seagrasses. Marine plants grow in many habitats, but their distribution is limited by the availability of light, substrate and oxygen.

Most marine plants are found from the'ntertidal zone to depths of 30 to 40 meters. Beyond this depth there is usually insufficient light for photosynthesis due to the light-absorbing properties of seawater (Dawson, 1966). Red algae, however, are adapted to low light levels and have been dredged from depths -of 170 meters in clear tropical water (McConnaughey, 1970).

Marine macrophytes usually require a hard substrate for attachment and therefore seaweed is rarely found growing in shifting sands or soft mud. Along the east coast of Florida, seaweed is found on rock outcroppings, worm reefs, shell rubble, and artificial substrates.

Algae are usually sparse on and near coral reefs due to grazing by herbivorous reef fish.

F-1 I

I I

I I Water temperature may limit the growth of marine plants directly by affecting the rate of photosynthesis and indirectly by altering the solubility of oxygen in the water. As a result, many marine plants tolerate only a narrow temperature range (Dawson, 1966).

MATERIALS AND METHODS

Aquatic macrophytes were collected on 14 March, 2 June, 7 Sep- tember, and 4 December at each of the six offshore stations during

1977 (Figure F-1). Each sample was collected by towing a box-type dredge (46 cm x 46 cm x 25 cm) along the ocean bottom for five minutes. The speed of each tow was recorded and used to compute the surface area sampled. Depending on tow speeds, the approximate area sampled ranged from 175-200 m~. Duplicate samples were taken at each

station and preserved with a buffered 5X formalin-seawater solution in labeled containers..

The preserved samples were sorted in the laboratory,,and attached macrophytes were scraped from shell and rubble surfaces. Macrophytes were identified to the lowest possible taxon, and representative

material was retained as voucher specimens. Species identifications were according to Taylor (1960).

RESULTS AND DISCUSSION guantitative analyses were not c'onducted because insufficient

algae was collected. Only qualitative species lists were prepared for each sample. F-2 I

I I I

I I The offshore stations, '0 to 5 (Figure F-l), are open areas of shell hash with very little hard substrate for algal attachment. All of the algae collected were found on rubble and shell fragments. The algae were often tom or stunted, probably due to mechanical damage from the dredge, ocean currents, or the unstable substrate.

Twenty-eight species of algae were collected during 1977 (Table

F-1). The Rhodophyta, or red algae, is the largest and most diverse group of marine plants and comprised 46'A of the species collected. This distribution is normal because almost all red algae are benthic, attached forms (Dawson, 1966), and the dredge method of collecting macrophytes selects for attached algae. The bushy red algae of the genera agardhielza. and Gracilaria have strong disklike holdfasts as young plants and were often found attached to shells and rocks.

Subtropical and tropical algal associations typically show seasonal variations. Species diversity and abundance are 'usually greatest in summer and early fall. Hutchinson Island is located in the subtropical zone (Phillips, 1961) and the algae reflect the characteristic seasonal trends of this latitude. Small amounts of algae were found only at Station 1 in March (Table. F-2). Algae was collected at all stations in June (Table F-3) and at all stations except Station 5 in September (Table F-4). Algal diversity decreased in December and algae was collected only at Stations 4 and 5 (Table

F-5). During 1976 (ABI, 1977) and 1977, algal diversity was lowest

F-3 I

I in Harch and highest in September. The June 1977 samples, however, were more diverse than those from June-1976. Reproductive algah were collected in September.

No differences in the number of algal species collected were noted between stations. The only trend noted during the'tudy was the seasonal decrease of algal diversity during the winter and early spring months. This trend is unrelated to power plant operation.

Algal growth at all stations is limited primarily, by the lack of substrate. Benthic algae in this offshore area are not important primary producers. The open shifting ocean floor off Hutchinson

Island is not a productive area for algae, and material collected was therefore insufficient to make a quantitative evaluation of the benthic macrophyte community. No power plant operation effects were noted on the offshore macrophyte community.

F-4 l LITERATURE CITED

ABI. 1977. Ecological monitoring at the Florida Power 8 Light Co. St. Lucie Plant, annual report 1976. Vol. l. AB-44. Pre- pared by Applied Biology, Inc., for Florida Power 8 Light Co., Miami.

Dawson, E. Y . 1966. Marine botany. Holt, Ri nehart and Winston, Inc., New York. 371 pp.

McConnaughey, B. H. 1970. Introduction to marine biology. C.V. Mosby Co., St. Louis. 449 pp.

Phillips, R. C. 1961. Seasonal aspects of the marine algal flora of the St. Lucie inlet and adjacent Indian River, Florida. quart. Jour. Fla. Acad. Sci. 24(2).

Taylor, W. R. 1960. Marine algae of the eastern tropical and,subtropical coasts of the Americas. Univ. of Michigan Press. 870 pp.

F-5

I 80 "15 '

~,'.:t O

~ o ~ .s "A

27'20~—

FPL ST. LUCIE PLANT

Figure F-1. Locations of macrophyte sampling stations, 1977. I

I TABLE F-1

MACROPHYTE SPECIES COLLECTED BY DREDGE AT OFFSHORE STATIONS ST. LUCIE PLANT 1977

CHLOROPHYTA (green algae) Chaetomorpha Sp. Cladophora Sp. Cladophoropsis SP. Codi um decorticatum C. isthmocladum Halicysti s Sp. Lyngbya Sp. Rhi zoclonium Sp. Ulothrix Sp. Ulva lactuca

PHAEOPHYTA (brown algae) Dictyota SP. Dilophus gui neensis Ectocarpus rhodochortonoi des Sargassum Sp. Sphacelari a furcigera

RHODOPHYTA (red al gae) Acanthophora spi ci fera Ceramium SP. Chondria SP. Eucheuma Sp. Gracilaria Sp. Grateloupia Sp. Halymenia Sp. Hypnea Sp. Laurencia Sp. Polysiphonia subtilissima Polysi phonia Sp. Soliera Sp. Wrangelia SP.

F-7 TABLE F-2

MACROPHYTE SAMPLING RESULTS ST. LUCIE PLANT 14 MARCH 1977a

Station S ecies

no algae collected

Eucheuma Sp. Ulothrix sp.

no algae collected

no algae collected no,algae collected

no algae collected a Two replicates per station, approximate area sampled was 175 m2 per replicate.

F-8 I

}i TABLE F-3

MACROPHYTE SAMPLING RESULTS ST. LUCIE PLANT 2 JUNE 1977a

Station echoes

Ceramium Sp. Chaetomorpha Sp. Cladophora Sp. Codium isthmocladium Dictyota SP. Lyngbya Sp. Rhizoclonium Sp.

Polysi phonia SP. Dictyota Sp. Zyngbya SP.

Ceramium SP. Chaetomorpha Sp. Codium SP. Dictyota Sp. Hypnea SP. Polysiphonia SP. Sargassum SP. Soliera SP.

Halicystis SP. Po2.ysj'phoni a Sp. Sargassum Sp. Soliera Sp.

Cladophora Sp. Cladophoropsi s Sp. Dictyota Sp. Polysiphonia Sp. Rhi zocloni um Sp. Soliera Sp. Acanthophera spi cifera Chaetomorpha Sp. Cladophora Sp. Ectocarpus rhodochortonoides Laurencia SP. Sphacelaria furcigera

a Two replicates per station, approximate area sampled was 190 m2 per replicate.

F-9 TABLE F-4

MACROPHYTE SAMPLING RESULTS ST. LUCIE PLANT 7 SEPTEMBER 1977a

Station S ecies

Cladophora SP. Codi um decorti catum Di lophus guineepsis Grateloupia Sp. Polysiphonia subti lissima Soliera Sp. Sphacelari a furcigera Ulva Iactuca

Cerami um SP. Cladophora Sp.„ Codi um decorticatum . Halymeni a S P. Soliera SP. Ulva lactuca

Cerami um SP. Chondria SP. Cladophora Sp. Codi um decorticatum C. isthmocladium Dilophus guianeensi s Eucheuma Sp. Gracilaria SP. Halymenia Sp. Laurencia Sp. Polysiphonia Sp. Rhi zocloni um Sp. Sargassum Sp. Soli era Sp. Sphacelari a furci gera

Cerami um SP. Codi um decorti catum Di lophus gui neensis Eaurencia Sp. S hacelaria furci era a Two replicates per station, approximate area spmpled was 190 m2 per replicate. TABLE F-4 (continued)

QACROPHYTE SAMPLING RESOLTS ST. LUCIE PLANT 7 SEPTEMBER 1977a

Station S ecies

Cerami um SP. Cladophora Sp. Codi um decorticatum Dilophus SP. Eucheuma SP. Gracilaria SP. Halgmenia Sp. Polysiphonia Sp. Rhizoclonium Sp. Sphacelari a furcigera Ulya lactuca

no al ae collected

Two replicates per station, approximate'rea sympled was 190 m~ per replicate. TABLE F-5

MACROPHYTE SAMPLING RESULTS ST. LUCIE PLANT 4 DECEMBER 1977a

Station S ecies

no algae collected

Ceramium Sp. Chaetomorpha Sp. Rhizoclonium Sp. Vrangelia SP.

Sargassum Sp.

a Two rgplicateq per station, approximate area sampled was 200 m~ per replicate.

F-12

R. ~WIITER UALITY

INTRODUCTION

This study was designed to monitor the physical and chemical parameters of the aquatic habitat at the St, Lucie Plant. The study of physical and chemical parameters provides a measure of water quality and potential productivity. Water quality measurements integrated with biological data provide a unified view of the ecosystem and facilitate the examination of the relationship between the environment and the marine fauna.

The presence of biologically important micronutrients such as inorganic nitrogen species, silicates, phosphates, and total organic carbon is essential for the growth of phytoplankton populations (Yentsch, 1962). Salinity and temperature are also important to the stability and growth of sedentary and motile fauna. Yaria- tions in these parameters may cause changes in the metabolism of organisms. Thus, temperature, salinity, and nutrients often have a synergistic effect on the physiological state of marine fauna.

PHYSICAL PARAMETERS

Materials and Methods Physical oqeanographic parameters, including water temperature, salinity, dissolved oxygen, turbidity and percent transmittance

G-1 II

I of light, were measured at designated offshore stations at surface, middle, and bottom depths. Stations located within the canals were sampled for temperature, salinity, dissolved oxygen and turbidity at surface and bottom depths. Station locations are indicated on

Figure G-l, and parameters measured at each station are given in Table G-l.

Water Tem erature Monitorin continuous

Ryan-Peabody thermographs were calibrated by comparing meter readings with mercury-in-glass thermometers. Calibrations were made at the beginning and end of a one-month recording period.

Thermographs were placed in the water adjacent to the offshore intake and discharge structures at subsurface depths. Data were recorded in 'F.

Water Tem erature Monitorin in situ Water temperatures were recorded in situ at biological sampling stations with a Yellow Springs Instrument (YSI) Model 33 salinity, conductivity, and temperature meter. Data were recorded in 'C.

~Salinit

Salinity was measured by one of two methods:

l. A YSI salinity-conductivity-temperature meter Model 33

with a 50-foot cable and probe was calibrated prior to

use by immersion in water containing known amounts of

G-2

commercial artificial sea salts. Salinity data were recorded in the field as parts per thousand ('/„).

2. An American Optical refractometer (Model 10419 Goldberg,

Temperature Compensating) was calibrated from stock

solutions of known sea-salt concentrations. Data were recorded in '/oo in the laboratory..

~Di 1 do

A YSI Model 54 or 518 meter with a 50-foot cable and probe was calibrated by readings taken from oxygen-saturated sea water. Data were recorded from readings in situ, at designated depths, in ppm (mg/1).

~Turbidit

Mater 'turbidity was measured with either an Interocean Model

515 TR turbidity meter or a Hellige Tuirbidimeter. Accuracy of the

Interocean meter was determined by calibrating the probe which was immersed in distilled water. The Hellige meter was precalibrated by the manufacturer. Offs/ore turbidity was measured in sieu, whereas canal samples were returned to the laboratory for analysis. Turbidity was measured as a function of light attentuation over a fixed path length as recommended by EPA (1974). Data were expresse4 as percent transmittance of light.

G-3 l

l Conventional units of turbidity are based upon FTU (Formazine

Turbidity Units) and may be related to percent transmittance values by the following: bx X Transmittance = ae

where: a = gg.6g

b = -0.0254,

and x = FTU (Formazine Turbidity Units).

Luminosit Li ht Transmittance Luminosity (light transmittance through the water column) was recorded with an Interocean Marine Illuminance Meter Model 510 at offshore stations. Comparisons between incident solar radiation at the surface and at various depths were recorded as luminosity in foot-candles and expressed as percent transmittance of light. Data were taken at surface, middle, and bottom depths at all offshore stations.

Current Velocit

Surface current speed and direction were measured at offshore stations with a General Oceanics Model 2030 digital flowmeter lowered to 0.5 m depth. Surface currents were recorded in'm/sec. After a one-minute reading, direction was estimated with a magnetic marine compass.

G-4 I

I Wind Direction, Wind Velocit, and Cloud Cover

Wind direction and velocity were estimated at the same time biological samples were taken. Cloud cover was estimated and expressed as clear, partly cloudy, rainy, or by similar descriptors.

Results and Discussion Salinity, temperature, dissolved oxygen, and turbidity data were taken to provide supplementary information to the biological aspects of the program. In the event of unusual or extraordinary observations made of the biotic communities, physical parameter data could delineate plant-related causes versus natural phenomena. Statistical procedures used in the following discussion of physical parameters were performed at a=.05.

Water Tem erature Monitorin continuous

The daily ranges of water temperatures continuously recorded at

ocean intake and discharge structures by Ryan-Peabody thermographs are

shown in Appendix Figures O-l and 0-2. Thermograph readings at the

intake structure ranged from a low of 57'F in January to a,high of 87'F in July.

The available data indicate that the increase in discharge temperature above ambient oceanic intake temperatures was greatest in

late summer with average monthly aT's of 2.0'F and 2.4'F for August

and September. Measurements from early summer exhibited the lowest

G-5 average monthly aT's of 0.6'F and 0.5'F (June and July), while the average aT in March was 1.8'F.

Water Tem erature in situ

Water temperatures were measured concurrently with nutrient and phytoplankton samplings at offshore Stations 0 through 5 and at Sta- tions 11 and 12 in the intake and discharge canals, respectively.

These data appear in Appendix Table 0-1. Surface intake canal temperatures varied from 15.5'C in January 1977 to 29.2'C in September 1977.

During 1977, temperatures were between 10,4 and 13'C higher in the discharge canal than in the i ntake canal on dates when nutrient and phytoplankton samples were taken. Hater temperatures at offshore stations ranged from 16.3'C in January at Station 0 to 30.5'C in July at Station l.

Stations 0 through 5 were statistically compared to detect temperature differences both between stations and between seasons.

E Analysis of variance (ANOVA) indicated no significant differences among the six offshore stations at either surface, middle, or bottom depths, but seasonal variations, shown in Figure G-2, were significant. This graph also shows a vertical stratification of temperature which is especially noticeable in the summer months.

~sal i ni a Salinity values measured for the six offshore stations as well as for the intake and discharge canal stations (Appendix Table 0-2)

G-6 I were found to be in a narrow range between 35.00'/ and 36.62'/

ANOVA indicated no significant differences among the six offshore stations at surface, middle, or bottom depths for salinity, but seasonal variation was detectable at each depth.

Dissolved Ox en

Dissolved oxygen values were measured monthly at the six offshore stations and at Stations ll and 12 in the intake and discharge canals, respectively. These data are listed in Appendix Table 0-3.

Dissolved oxygen values ranged from 4.6 to 7.9 mg/liter during the

1977 study. ANOVA indicated no significant differences among the six offshore stations for dissolved oxygen at surface, middle, or bottom depths, but as with the other physical parameters, there was a detectable seasonal variation.

~Turb idi t Turbidity measurements made during 1977 for the six offshore stations and the intake and discharge canals appear in Appendix Table

0-4. ANOVA detected no significant differences among the six offshore stations at surface, middle, or. bottom depths. Differences were detectable between monthly samplings, with the greatest turbidities occurring in the fall and winter and then diminishing in the summer months.

Li ht Transmittance Offshore light transmittance data are listed in Appendix Table 0-5. Values are given for each of the six stations at surface, middle,

G-7 and bottom depths as well as on the deck of the boat.

Oceano ra hic Measurements

Surface current velocities, wind direction and velocity, cloud cover information, and tidal and lunar phase data were collected concurrently with each monthly phytoplankton sampling. These data are maintained in the laboratory and are not included in this report.

CHEMICAL PARAMETERS

Materials and Methods

Samples of water for nutrient analyses were collected monthly at offshore Stations 0, 1, 2, 3, 4, 5 and Stations ll and 12 located in the intake and discharge canals, respectively (Figure G-1) . Dupli- cate samples were taken from surface, middle, and bottom depths.

Surface samples were collected by dipping, and subsurface samples were either pumped or sampled with a Niskin bottle. Water samples to be analyzed for ammonia nitrogen, nitrate nitrogen, nitrite ni,trogen, reactive si lica, and orthophosphate were passed through 0.45'embrane filter, placed in acid-washed polyethylene bottles, and quickly frozen. Water samples to be analyzed for total organic carbon were processed similarly but were spiked with 5 ml of concentrated sulfuric acid

(HzSO>). All chemical analysis samples were shipped to the laboratory on the day of collection..

G-8 I Methods of analysis used to measure these selected nutrients appear in either APHA (1976), EPA (1974), or Strickland and Parsons

(1972). A summary of the parameters analyzed and the respective methods is given in Table G-2. Statistical procedures used in the following discussion of chemical parameters were performed at a=.05.

Res ul ts and Di s cuss ion

The distribution of nutrients in the marine environment is a function of diffusion, currents and biological turnover. Nearshore nutrients are generally considered to be well-mixed and homogeneous as a result of turbulence induced by winds or currents (Bowden, 1970).

High concentrations of ocean nutrients are spatially limited and

usually associated with upwelling (Spencer, 1975), a river-ocean inter-

face (Stefansson and Richardson, 1963), or ocean waste disposal

out-'„'alls (EPA, 1971).

The results of analyses for ammonia nitrogen (NH~-N),, nitrate

nitrogen (NOq-N), nitrite nitrogen (NOz-N), reactive silicates (Si0z),

orthophosphates (PO~-P), and total organic carbon (TOC) from monthly

collections of seawater are presented in Appendix Tables 0-6 through 0-7.

Each chemical parameter was independently compared over the

entire year by a two-way analysis of variance. Offshore Stations 0

through 5 were statistically compared to detect significant differences (a=.05) both between stations and between sampling periods (seasonal

G-9 I I I I

I variations). These statistical comparisons were performed independently for surface, middle, and bottom depths. The results of these statistical analyses are summarized in Table G-3. With the exception of silica measurements at the bottom depths, no significant differences were found among the six offshore stations (0-5) for any chemical parameter at any depth. With the exception of surface TOC and bottom nitrite measurements, significant differences betweeh months were found for all chemical parameters at each depth.

Results of nutrient concentrations reported by Worth and Hollinger (1977) for the nearshore coastal environment adjacent to the

St. Lucie Plant between February 1972 and August 1973 compare very favorably with the results compiled for 1977 by Applied Biology, Inc.

The approximate nutrient concentration ranges for the 1972-1973 period are given below:

NHs-N <0.01 - 0.09 mg/liter NOs-N <0.01 - 0.075 mg/liter, I NOz-N <0.001 - 0.010 mg/liter Si0z 0.05 - 1.5 mg/liter POg-P <0.01 - 0.5 mg/liter

No significant differences in nutrient concentrations were detected among offshore Stations 0-5 during 1977. However, seasonal variations at surface, middle, and bottom depths were found to be significant (Figures G-3 through G-8). The ranges in concentration for each nutrient during the 1977 period are very similar to those in the 1972-1973 data.

Figures G-3 through G-8 show that armonia and nitrate concentrations increase in late fall and winter, silica reaches a maximum in late summer, and total organic carbon peaks in the spring, while nitrite and phosphate show only small increases in fall and winter months, respectively.

, Nutrient concentrations measured in the intake and discharge canals (Stations ll and 12) were statistically compared to control

Station 0 to determine differences either between stations or between monthly sampling periods. The only significant differences detected between stations were for surface NH>-N concentrations. This parameter was significantly greater at Stations ll and 12 than at Station 0, while no difference was detected between Stations 11 and 12. Significant seasonal variations were found'for each nutrient being analyzed.

SUMMARY Concentrations of nutrients in the nearshore environment adjacent to the St. Lucie Plant, as judged by monthly samples collected at the six offshore stations, are dispersed homogeneously but vary significantly with respect to time. Statistical analysis of nutrient concentrations measured monthly at the six offshore stations, which include a distant control station, indicates that the operation of the I

I I

I Ii

I St. Lucie Plant has no significant effect on the selected nutrients measured in this study. The yearly range in nutrient concentrations compares favorably with data collected from similar locations during

1972-1973; and no significant differences (a= .05) were found when

Stations 1-5 were compared with the control station (0).

Similarly, no significant differences (a=.05) were found among the six offshore sampling stations for temperature, dissolved oxygen, salinity, or turbidity measurements. Even though water with a differing physical parameter makeup is discharged into the nearshore environment by the St. Lucie Plant, the effect on the measured parameters, as judged from these statistical comparisons, appears to be minimal.

Seasonal variations were significant for all the physical parameters, as expected, just as with concentrations of the selected nutrients.

G-12 LITERATURE CITED

APHA. 1976. Standard methods for the examination of water and wastewater, 14th ed. American Public Health Association, Washington, D.C. 874 pp.

Bowden, K.F. 1970. Turbulence II. Oceanogr. Mar. Biol. Ann. Rev. 8:11-32.

EPA. 1974. Proceedings of seminar on methodology for monitoring the marine environment. Environmental Protection Agency, Office of Monitoring Systems Program Element No. 1HA326. Washington, D.C.

EPA. 1971. Limitations and effects of waste disposal on an ocean shelf. Grant 16070EFG. U.S. Environmental Protection Agency, Water Pollution Control Res. Ser.

Spencer, C.P. 1975. Nutrient distributions. Pages 245-300 in J.P. Riley and G. Ski rrow, eds . Chemical oceanography, Vol. 2. Academic Press, New York.

Steffansson, 0., and F.A. Richardson. 1963. Processes contributing to the nutrient distributions of the Colombia River and Strait of

, Juan de Fuca. Limnol. and Ocean. 8(4):394-410.

Strickland, J.D., and T.R. Parsons. 1972. A practical handbook of seawater analysis. Fish. Res. Bd. Canad. Ottawa, Bulletin No. 167. 310 pp. Worth, D.F., and M.L. Hollinger. 1977. Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. III. Physical and Chemical Environment. Florida Marine Research Publications, 23. Florida Department of Natural Resources, St. Petersburg, Florida. Yentsch, C.S. 1962. Marine plankton. in R.A. Lewin, ed. Physiology and biochemistry of algae. Academic Press, New York.

G-13 I I

l 80 "i5

';O

03 '-::. O6 g

~ ~ g

~ I 8 1 04

' \ O

~ ~ 27'20~—

FPL ST. LUCIE PLANT O

~ ~ O 0 O~

Figure G-1. Locations of water quality sampling stations, 1977. 30.0

o SuRFACE

~ 28.0 lllD-DEPTH o BDTTDH 4

26.0

0 24.0 4

22.0

20.

18.0 0 ~0

15.0 J A S N 1977 Figure G-2. Mean temperature values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. o SURFACE ~ HlD-DEPTH

BOTTOH

0$ 4

OO OI~

OIO 01 OS 0

J F M A M J J A S 0 .1977 Figure G-3. Mean ammonia values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. I

I I

I All values <0.1

0.012

o SURFACE ~ HID-DEPTH

0.010 ~ B0TTDH

5 Cl ~J 0.008

0 006

OO CC

0.00< OO

0.002 OO OO Os

Oat Oat

J F M A M J J A S 0 1977 Figure G-4. Mean nitrate values for nearshore Stations 0-5 combined, St. Lucie Plant-. l977. 0 SURFACE

~ HID-DEPTH

~ BOTTDH

OSS OSS

OSS OSS OSS OSS OSS OSS OSS OSS OSS

J M A M J J A S 0 1977 Figure G-5. Mean nitrite values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. I I

I 0.5 o SURFACE 4 ~ f3ID-DEPTH 0

04 e BDTTDH l Cl

0.3 R

V) 0 0.2 Co vl

0.1 0

J 1977 Figure G-6. Hean silica values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. 0.04

o SURFACE ~ HID-DEPTH

0.03 ~ BOTT0H

0$$

oao 0$ $ 0$ $ 0$ $ 0$ $ 0$ $ 0$ $ 0$ $ OS'$ $

J F M A M J J A S N 1977 Figure G-7. Mean phosphate values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. Im I II

I )d.oo

14.00 o

12.00 o SURFACE ~ HlD-DEPTH

C 4 ~ ~I 80TTDH 10.00

CO 8.00 0 4 CD ?:

CD IX d.oo

0 o o4

J F M A M J J A S 0 N 1977 Figure G-8. Mean total organic carbon values for nearshore Stations 0-5 combined, St. Lucie Plant, 1977. I

I TABLE G-1

PHYSICAL/CHEMICAL PARAMETERS MEASURED FOR EACH STATION ST. LUCIE PLANT, 1977

Offshore Offshore Parameter 0 1 2 3 4 5 6 7 8 ll 12 intake dischar e water temperature (continuous) water temperature (in situ) salinity dissolved oxygen turbidity luminosity current velocity wind direction, velocity, cloud covera v'' tidal cycle, lunar phases N-NOs N-N02 N-NHs Si-SiOg P-POg TOC

Data records are maintained in the laboratory and are not. included in this report. I TABLE G-2

METHODS OF ANALYSIS USED TO MEASURE SELECTED WATER PARAMETERS ST. LUCIE PLANT 1977

Parameter Metho eference

Ammonia nitrogen (NHs-N) Indophenol Strickland and Parsons 1972, p. 87

Silicates (SiOq-Si) Heteropoly bl ue APHA, 1976, p. 490

Nitrate nitrogen (NOs-N) Brucine APHA, 1976, p. 427 a Cadmium Reducti on APHA, 1976, p. 423

Nitrite nitrogen (NOq-N) Diazotization APHA, 1976, p. 434

Ortho-phosphate (POq-P) Ascorbic acid APHA, 1976, p. 481

Total organic carbon (TOC) Combustion-infrared APHA, 1976, p. 532

a This method used after March 1977. TABLE G-3

SUMMARY OF STATISTICAL ANALYSIS OF PHYSICAL AND CHEMICAL DATA ST. LUCIE PLANT, 1977

Analysis of variance Analysis o variance between stations 0-5 between months Parameter Surface Mid-de th Bottom Surface Mid-de th Bottom

NHs-N NS NS NS

NOs-N NS NS NS

NO?-N NS NS NS

SiOz NS NS *

POo-P NS NS NS

TOC NS NS NS

Sal inity NS NS Dissolved Oxygen NS

Temperature NS NS NS

Turbi di ty NS NS * g * * Significant at a=0.05. NS = not significant.

G-24 H. NESTING TURTLES

INTRODUCTION

The Florida Power 8 Light Company ( FPL) has been studying marine turtles since 1971 to evaluate potential impacts of the construction and operation of the St. Lucie Plant on turtle nesting behavior. When plant construction began in 1971, FPL in conjunction with the Florida Department of Natural Resources (FDNR) initiated a long-term 'study of the nesting behavior of sea turtles, principally

Atlantic loggerheads, on Hutchinson Island. This 37.5 km stretch of sandy beach, which extends from St. Lucie Inlet to Ft. Pierce Inlet

(Figure H-l), may be the largest marine turtle rookery in the United

States (NMFS, 1976).

It is of concern to FPL that the presence of the St. Lucie

Plant and the warm water discharge from the plant's cooling system do not adversely affect the reproductive behavior of marine turtles.

Since very little is known about their behavior, research was conducted during the summer nesting season on alternate years from 1971 through 1977. Observations of nesting and predation were used in conjunction with tagging and recapture studies to produce data on the nesting success and site specificity of female sea turtles and an assessment of the effects of the St. Lucie Plant on the Hutchinson Island rookery.

H-1 Harine Turtles at Hutchinson Island

Three species of marine turtles are known to nest on Hutchinson

Island. The most common is the Atlantic loggerhead turtle (careeta caretta), followed by the green turtle (chelonia midas) and the leatherback turtle (Dermochelys coriacea). The leatherback turtle is

classified as an endangered species by the Federal government [Federal Register 41(208):47180-47198j, and all marine turtles are protected

by Florida Statutes (307.12; 1974).

Each year, from about May to September, hundreds of loggerhead turtles nest along the beaches of Hutchinson Island. In addition to

loggerheads, about 8 to 15 green turtles and several leatherback turtles were observed nesting during the study years. Leatherback turtles nest infrequently along the U. S. Atlantic coast, so Hutchinson Island

may be an important U. S. Atlantic rookery for this species.

In view of the declining world populations of marine turtles

caused by fishing pressures and loss of nesting habitat through coastal

development ( IUCN, 1969; IUCN, 1971; NMFS EIS draft, 1976), the Hutchi nson Island rookery is of special importance in mai ntaining sea turtle populations. Loss of this rookery would seriously deplete the populations of these protected species in the United States.

H-2 MATERIALS AND METHODS

Nine segments of Hutchinson Island beach (Figure H-l), each

1.25 km long and roughly equidistant, were surveyed 5 to 7 days per week during the marine turtle nesting season. Although the nesting season varies somewhat, it usually begins in early May and continues through the end of September. Since sea turtles lay their eggs at night, the nesting beach was patrolled at night from about 9:00 p.m. to 5:00 a.m. Small off-road vehicles provided beach transportation so that all survey areas could be patrolled several times during the course of an evening.

When turtles emerged from the sea to nest on the beach, their location was noted. Care was taken not to disrupt turtles prior to nesting. Once a turtle had begun to deposit eggs or was seen return- ing to the sea, an identification tag (Monel self-piercing, National

Band and Tag Co., No. 4-1005, size No. 49) was applied on the right foreflipper. Tagging was conducted south of area 4 in 1971, 1973 and

1975, and in areas 2 through 7 in 1977. The length and width of each turtle was measured with calipers, and the general physical condition of each individual was noted. Turtles were not weighed because of the difficulty in placing specimens, which may weigh in excess of a hundred kilograms, upon scales. Nest locations were marked with numbered stakes in order to relocate them.and monitor predation on eggs.

H-3 I

I Often a turtle will crawl up on the beach and even begin nest excavation only to return to the sea without depositing eggs. Extraneous light, sound, movement or other factors increase the like- lihood of these "false crawls." Although the presence of biologists

in the turtle rookery areas at night may have affected turtle behavior

by increasing the number of false crawls, the effect would be constant throughout the survey areas.

The study data were derived from daytime nest counts, raccoon predation of nests, and nighttime tag and recapture studies over four

alternating years. The intensity and efficiency of the daytime nest

count and predation study remained relatively constant over the entire study period. However, the nighttime tagging studies in 1971 and 1973

were affected by variables such as study effort intensity, numbers of available observers, and study efficiency (differing modes of transportation). Accordingly, comparisons between each of the four study years should be interpreted with caution.

RESULTS AND DISCUSSION

Nes ti n Activit 'on Hutchins on Is 1 and Nesting site selection in marine turtles is an integral part of the nesting behavior. It is thought that many environmental fac-

tors, some of which are listed in Table H-l, play an important part

in this behavior. A review of these factors indicates that only

beach stability shows a trend with the observed variation in nesting H-4 activity. Worth and Smith (1976) related year-to-year changes in

'I nesting density to variations in beach topography. Historically, the northern portion of Hutchinson Island has been subject to heavy beach erosion that produces a steep-sloped beach which may be as little as

3 m wide. Turtles encountering this beach are often rebuffed by insurmountable cliff-like ledges and nest elsewhere. In addition, high tides along areas 1 through 3 frequently wash the beach plain, the area of beach from mean high water to the base of the primary dune face, and may cause severe erosion, with resultant nest loss, throughout the nesting season.

By contrast, the southern half of the island (areas 6-9) has relatively wide, gently sloping beaches that are 30 to 40 m in width, the widest being in area 9. It appears that female turtles may select a nesting site on the basis of beach length, slope, stability, and accessibility.

Coincident with the general trend of decreasing north-to-south erosion rates (increasing beach stability) was a trend of increased nesting activi ty ( Figure H-2). This gradient of increasing activity was observed in all survey years.

To test the validity of the apparent relationship of topography with nesting activity, a statistical model was generated using observations from the four study years. A 1 inear model was fit to the

H-5 I

I I I I

I I I

I I number of crawls as a function of nesting area location. Different slopes and intercepts for each year were permitted. This model obtained a multiple correlation coefficient of 0.8978 and accounted for 80.61 of the variability in crawls. A strong positive correlation was demonstrated between nesting activity and topographical suitability of the beach.

With the above model, the number of crawls at area 4 (nearest the St. Lucie Plant) was predicted for each year and a 95K confidence interval was constructed for this number. Predicted and observed crawl activities were compared to see how closely the observed number of turtle crawls compared with those predicted by the linear model

(Table H-2). In 1975, observed crawl activity in area 4 was only 58K of the predicted number. The other study years showed crawl activity levels reasonably close to predicted values. The 1975 decline in crawl activity could most probably be attributed to the construction of the St. Lucie Plant offshore intake and discharge systems. During the 1975 study, construction crews were operating on a 24-hour schedule using drag lines and other heavy equipment with strong lights. It is reasonable that this activity made area 4 less desirable as a nesting beach. In 1977, however, nesting activity in this area returned to the general pattern observed during the other study years.

H-6 Nestin Success at Hutchinson Island Nesting success is defined as the ratio of successful nesting to the total number of nesting attempts. Nesting success distribution along the Hutchinson Island beaches was examined to determine whether this ratio in the vicinity of the St. Lucie Plant was significantly different from that in other areas of the island.

Nesting success data (Figure H-3) demonstrated significant variations (P=0.05) between nesting areas within three of the study years (false crawl data were not taken in 1971). Nesting success was reduced throughout the island in 1975 and 1977. This reduction cannot be readily explained. Although nesting success declined in area 4 during 1975 and 1977, the percentage of successful nests was similar,

51.4$ and 53.5/, respectively. Variables that can affect nesting trends, discussed earlier (Table H-l), may also influence nesting success. An apparent reduction in nesting success in 1977 was observed at the southern half of the beach, particularly in nesting, areas 6, 7 and 8. Here, nesti ng success was less than 505 of nesting attempts.

Probable causes were a rapid increase in commercial development of beach properties near these areas. These developments, steadily increasing since the early 1970's, provide increased levels of human acti vi ty along the beaches at night. Caldwell ( 1962) has documented similar declines in nesting due to beach development along Jekyll Island in Georgi a.

H-7 I

I Site S ecificit

Site specificity, the tendency of a turtle to return accurately on successive nestings to the locality of previous nestings, has been well documented in green turtles (Carr, 1972). Evidence suggests that loggerhead turtles, although not as site-specific as green turtles, do return to the same location with each successive nesting attempt (Caldwell et al., 1959; Worth and Smith, 1976).

Site specificity was studied on Hutchinson Island in 1973 and

1977 by calculating the distance between successive nesting attempts of tagged turtles. Data from 1973, when the tagging effort was south of the plant, was compared with 1977 tagging data from areas in the vicinity of the plant. The calculated mean distances between successive nesting crawls of 4.6 km (2.9 mi) in 1973 and 4.1 km (2.6 mi) in 1977 are very similar and approach values reported by Hughes and Brent

had no ( 1972). These findings indicate that plant operation in 1977 observable effect on the site-specificity behavior of loggerhead turtles.

Renes tin Intervals

The time between two successive nestings of Atlantic loggerhead

turtles has been established at about 2 weeks (Caldwell, 1962; Hughes et al., 1967). This time interval varies considerably, possibly in response to changes in water temperature. Hughes and Brent (1972)

indicated that as seasonal water temperatures increased, the renesting interval for loggerheads decreased. The renesting interval for Hutchinson

H-8 I I

I I Island turtles in 1973 ranged from 11 to 17 days (Worth and Smith,

1976). During 1977, the renesting interval for turtles tagged in areas adjacent to the St. Lucie Plant ranged from 13 to 15 days. This similarity suggests that the St. Lucie Plant discharge had no observable effect on the renesting interval of loggerhead turtles.

Water Tem eratures and Onset of Nestin Season Variations in ambient water temperatures have been associated with changes in the timing of both nesting activity and nesting rates

(Hughes and Brent, 1972; Worth and Smith, 1976). During all four study years, the nesting season began when maximum ocean temperatures

ranged between 22 and 24.5'C (Figure H-4). A positive relationship

between rising water temperatures and increased crawl activity was observed at the onset of each nesting season at Hutchinson Island (Figure H-4). Crawl activity levels increased until June or July and then declined, despite generally rising water temperatures throughout the nesting season. Thus, ocean water temperatures appear.to exert

some influence on the level of nesting activity during the early weeks of the season. Evidence for this influence is strengthened by examin- ing the 1973 data, when cooler ocean temperatures in June coincided

with delayed crawl activity. When ocean temperatures increased in

July, a corresponding increase in crawl activity was, noted. The lower

water temperatures in June may have partially inhibited nesting until July, when the warmer waters coincided with a greater influx of nesting females. In contrast, increased nesting activity was observed

H-9 during the early nesting season periods of 1975 and 1977, when ambient ocean temperatures were warmer than those in the other years of observation.

The onset of the nesting season i n response to ocean temperatures could be further influenced by additional factors such as day length (photoperiod). Synergistic effects of temperatures and photoperiod on reproductive biology have been observed in other reptiles (Crews, 1975; Callard et al., 1972; Cloudsley-Thompson, 1971). If water temperature is the mechanism that triggers nesting activi ty, it follows that unseasonably warm water might induce premature nesting.

A source of warmed water is provided by the St. Lucie Plant offshore discharge structure, which emits a surface plume of water up to 3'C above ambient water temperatures. If premature nesting is induced by the plant's warm water discharge, why would this be of concern?

Marine turtle eggs must incubate at nest temperatures of 29-35'C in order to hatch, and increased mortalities can occur if temperatures are not optimal (Bustard, 1971). The percentage of

fertile eggs that mature and hatch is therefore influenced by the

time of year i n which they have been deposited. If turtle eggs were deposited too early in the year, the beach temperatures would not be warm enough to maintain the requisite temperatures. Since developing

turtles have no heat-regulatory mechanisms, they are dependent upon favorable location and ambient temperatures for survival. Eggs laid too early or too late in the nesting season would have considerably less opportunity to develop and hatch. Loggerhead turtle eggs usually hatch in about 49 to 62 days (Caldwell, 1962); warmer temperatures produce earlier hatching, and cooler temperatures extend hatching times (Hughes and Richard,'1974).

A more subtle factor, yet one equally important in terms of hatching success, is the condi tion of the sandy beaches in which the eggs must incubate. Nests laid too early or too late in the year are more likely to be destroyed by beach erosion. Beach erosion is more frequent during the fall, winter, and early spring when wind speeds increase and the direction changes to onshore, from the northeast.

Onshore winds increase sediment transport and erosion so that beach stability is reduced from September through early Hay. Nests which are exposed or broken up by waves do not survive. The marine turtle nesting season occurs duri ng this period of greatest beach stability.

To examine the hypothesis that the St. Lucie Plant warm water discharge may induce seasonally premature egg-laying, crawl activity observations at area 4 were compared with those in areas 1-3 and 5-9.

(The plant discharge structures are located offshore from area 4).

The median of crawl activity was calculated to identify the week in which exactly one-half of the turtles during each nesting season had attempted to nest. It should be noted that sea turtles do not begin nesting the same week each year, but the nesting season is reasonably I

I consistent in duration, about 20-21 weeks long. For purposes of comparison, the onset of the nesting season was identified as week no. 1 and the last week of nesting was designated as week no. 20 or

21, regardless of its posi tion in the calendar year.

Minor,differences were noted between years in the timing at which the nesting season began (Table H-3). Crawl activity (nesting crawls, false crawls and combined nesting plus false crawls) did not

begin or end uniformly throughout all areas during the years studied.

The week of median crawl activity ranged from week 8 to week 11 of the nesting season. 'The week in which median crawl activity occurred

in area 4 was similar to that in the remaining areas within each year.

Plant operation in 1977 did not appear to have a major impact on timing of nesting activity.

Predati on

The principal predator of marine turtle eggs on Hutchinson Island is the raccoon. Raccoons forage on the beaches at night, dig

open the nests and devour the eggs. Predation on nests varies from year to year. Predation in all nine survey areas destroyed 28K of

the nests in 1971 and 43.6/ in 1973. In 1975, predation destroyed only 20.8$ of the nests, but in 1977 predation losses increased to 38.65.

Predation rates by nesting area and year are shown in Figure H-5.

The low predation levels observed at areas 6 and 7 in all four study years were probably the result of commercial development and con- s tructi on that destroyed raccoon habitat. Preconstruction 1 and clearing for the St., Lucie Plant prior to 1971 also removed raccoon habitat, and jn 1971 nest predation in area 4 was lower than that in areas 3 and 5.

Predation (and the number of nests deposited) declined in

1975 in all areas. Construction activity may have inhibited raccoons wandering along the beaches in search of food. In 1977, when construction had been completed, predation increased at area 4 and all other areas. Predation rates were high in areas 1, 2, 3 and 9 throughout the four study years. These areas, at the northern and southern perimeters, are among the last remaining undeveloped areas. There- fore, large raccoon populations are found there.

Po ulation Size Estimates

Turtle population estimates are based on both the total estimated number of nests and the frequency of multiple renesti ng within the season. Hutchinson Island surveys have shown that the renesti ng frequency varies from one to four. The varied renesting frequency makes it difficult to estimate the population accurately. For this reason, earlier population estimates are probably inaccurate . Also, in any such survey only female sea turtles are sampled, so male components of the population are excluded. I I

I I Estimates of the total number of nests deposited by loggerhead turtles vary. Routa (1968) estimated that there were 5265 loggerhead turtle nests containing a total of 658,125 eggs along 36 kilometers of Hutchinson Island. His estimate was based on observations of 705 nests on three 1-mile stretches 'of beach. This estimate, however, did not allow for, the north to south variation in nest density noted on the island.

In the present study, variations in nesting density were taken into account by a curve which provided an estimate that the number of nests in 1977 on 32.8 km of Hutchinson Island beaches was 2108. This estimate was then adjusted to eliminate the females that appeared on

the beaches more than once. The renesting component of the population was derived by tag and recapture studies. The female loggerhead popu-

lation for 1977 was thus estimated from the ratio of the number of tagged turtles to the number of nests recorded from these tagged turtles. This yielded an estimated population of 1491 nesting

femal es.

H-14 LITERATURE CITED

Bustard, H. R. 1971. Temperature and water tolerances of incuba- ting sea turtle eggs. Brit. J. of Herpetology 4:196-8.

Caldwell, D. K. 1962. Comments on the nesting behavior of Atlan- tic loggerhead sea turtles, based primarily on tagging returns. quart. J. Fla. Acad. Sci. 25(4):287-302.

Caldwell, D. K., F. H. Berry, A. Carr, and R. A. Ragotzkie. 1959. The Atlantic loggerhead sea turtle, caretta caretta caretta (L.), in America. Bull. Fla. State Mus. Biol. Sci. 4(10):293-348.

Callard, I. P., S. W. C. Chan, and M. A. Potts. 1972. The control of the reptilian gonad. Am. Zoologist 12:273-287. Carr, A. 1972. Site fixity on the Caribbean green turtle. Ecol- ogy 53:425-429. Cloudsley-Thompson, J. L. 1971. The temperature and water relations of reptiles. Merrow Technical Library, Merrow Publishing Co., Ltd., Watford Herts, England. 148 pp.

Crews, D. 1975. Psychobiology of reptilian reproduction. Science 189:1059-1065.

Hughes, G. R., and B. Brent. 1972. The marine turtles of Tonga- land, 7. The Lammergeyer 17:40-62.

Hughes, G. R., A. J. Bass, and M. T. Mentis. 1967. Further studies on marine turtles in Tongaland, I. The Lammer- geyer 7:5-54.

Hughes, D. A., and J. D. Richard. 1974. PublicThe nesting of the Pacific Ridley turtle, kepi dochelys oji vacea on Playa Nancite, Costa Rica. Mar. Bio. 24:97-107.

IUCN. 1969. Marine turtles - proceedings of working meetings, marine turtle specialists. IUCN Publ. News Ser., Suppl. Pap. 20. 100 pp. 1971. Marine turtles - proceedings of 2nd working meeting, marine turtle specialists. IUCN News Ser., Suppl. Pap. 31. 109 pp.

NMFS. 1976. Proposal listing of green sea turtle (chesonia midas), loggerhead sea tul tie (caretta caretta), pacific I l

I Ridley sea turtle (repzdochelys olivacea) as threatened species under the Endangered Species Act of 1973. Draft EIS. National Marine Fisheries Service, Dept. of Commerce, Washington, D.C.

Routa, R. A. 1968. Sea turtle nest survey of Hutchinson Island, Florida. g. J. Fla. Acad. Sci. 30(4):287-294.

Worth, D. F., and J. B. Smith. 1976. Marine turtle nesting on Hutchinson Island, Florida, in 1973. Fla. Dept. Nat. Res. Mar. Res. Lab. No. 18:1-17.

H-16 I

I 80 0 15'0 e 1nlet 10''r o <,.„)

1 SSASE NNY ASA 2 , 1

-N-

4 p 8

22'2

FPL ST. LVCIE PLANT ~ 1

VS NNY 1

MALT0N.

JENSEN'EACH ".

0 E I 81 r

'.'' 1 0

2780' Inlet

Figure H-1. Locations of turtle nesting areas surveyed on Hutchinson Island. I M W W W W M M M

450 92Z223 1971 EZZZZB 1973 O 40O 1975 IRK='iR 1977

350

g 300

250

200

CD 150 oo

100

CD 50

3 4 5 NESTING AREA North end of Hutchinson Island Figure H-2. Total number of observed marine turtle crawls by nesting area and year, Hutchinson Island. C) C) 80 X

70 ~O, ~, ~ ~ ~ ~ ~ CD / cn ca 6p 0 'e ,0 CD I ~g

50 "a, ~ ~ ~ ''Once + ~ ~ ~ ~ ~ ~ eO I c/l 40

W CD I- c/I 3p UJ cx 1973 .~~ 20 ———1975 ~ ~ ~ ~ ~ ~ ~ ~ 1977

cg 10

1 2 3 4 5 6 7 8. 9 NESTING AREA ~ North end of Nutchinson Island Figure H-3. Percentage nesting success of marine turtles by nesting area and year, Hutchinson Island. (No false crawl data were recorded in 1971.)

H-19 I

I 30 29 28 gl ~ ~ ~ »»» ~ »Q» ~ ~ ~ 2 7

V'l

25 24 K~ 23 Q»' 22 X f

20 1971 %I 1084 //g 1973 ----- 1975

~ ~ ~ ~ / ~ ~ ~ 1 977 // 800 4 I I I 700 t

5 <00

C3 LLI 500

400 ~ CD I

P 300 O l» »' l» 200 \;

l» 100 I; j' le, ~ 4

Mar Apr May Jun Jul Aug Sep

Figure H-4. Comparison of marine turtle nesting activity to ocean water temperatures by month and year, Hutchinson Island.

H-20 I I I

I RO

Mo ~ ~ 40 ~ 0 ~ ~ C7 ~ ~ Vl ~ ~ ~ ~ V\ ~ ~ 4) ~ ~ ~ ~ ~ 4 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4C ~ t ~ ~ ~ ~ ~ ~ ~ ~ %P 4k ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 ~ I ~ ~ 20 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ K ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4P ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 ~ ~ ~ ~ ~ hd ~ ~ ~ ~ ~ ~ ~ ~ 0 ~ ~ 0 7$ 75 7t 7I 75 7t 71 't$ 75 7$ t5 7t 'tl 7$ 't$ 7t 71 7$ 7$ tt 71 t$ 75 'tt 75 7t 5 t

RKSTIRC ARIA RVRSKR ARO TSAR OF OSSKRVAFIORS

Figure H-5. Percentage of marine turtle nests destroyed by predation for each nesting area and year, Hutchinson Island. TABLE H-1

ENVIRONMENTAL FACTORS THAT MAY INFLUENCE NESTING OF MARINE TURTLES

a Nesting area and influence 2 3 9 Factor SMH SMH SMH SMH SMH SMH SMH SMH SMH

Long-term beach erosion Short-term beach erosion / Silhouette v' Lighting

Human activity

Dune height

S = slight influence; M = moderate influence; H = heavy influence. Silhouette refers to the shadow above the beach plain that results from the background lighting and skylight being excluded by the beach dune and/or beach front and dune-associated vegetation. TABLE H-2

NUtSER OF CRAWLS OBSERVED VERSUS CRAWLS PREDICTED BY LINEAR MODELING FOR EACH STUDY YEAR IN NESTING AREA 4 AT HUTCHINSON ISLAND ST. LUCIE PLANT 1971, 1973; 1975 AND 1977

o., observe No. pre scte ercentage of pre icte Year crawls 0 crawls p observed

1971 155 143 108.0A

1973 174 192 90.6Ã

1975 140 239 58.6X

1977 187 164 114.0/o

H-23 l

I l I l TABLE H-3

WEEK NUMBER FOLLOWING ONSET OF NESTING SEASON IN WHICH MEDIAN NESTING ACTIVITY OCCURRED BY YEAR AND AREA ST. LUCIE PLANT 1971, 1973, 1975 AND 1977

Areas 1-3 5-9 Area 4 Nesting False and False and season Nesting False nesting Nesting False nesting Year onset crawl crawl crawl crawl crawl crawl

1971 1st week 9 in May

1973 1st week 11 10 in May

1975 3rd week 8 in April

1977 1st week 9 10 in Ma

a Median nesting activity was calculated by N/2, where N = total no. of observations per season.

H-24 I

I I I

I I. HATCHLING TURTLE EXPERIMENTS

INTRODUCTION

The purpose of this study was to consider the influence of water temperature on hatchling marine turtles. Sustained swimming speed, which may be critical to the survival of the turtle, was used as a response indicator. The study also examined, in part, the physiological response of hatchlings to abrupt thermal changes, such as those that might be encountered in a discharge from an electric generating station, and the effect of these temperatures on the health and well-being of the hatchlings.

Atlantic loggerhead turtles (caretta caretta) use the barrier islands along the southeastern U. S. as nesting areas. During the summer, adult females crawl up the beach at night and deposit about

120 eggs in a 60-cm deep nest hole. Fifty to seventy days later, the eggs hatch and the hatchling turtles dig out of the nest and crawl to the ocean. While tracking studies have been limited, it is thought that the turtles migrate to the offshore weed line for food and protection (Fletemeyer, 1978). This terrestrial exposure of an otherwise aquatic organism and the offshore swim are extremely sensitive periods because of the susceptibility of the hatchling turtles to natural predation as well as to environmental alterations by the activity of man. Commercial development of the barrier islands along the east coast of Florida has promoted considerable concern for and study of the nesting habits, life history, and long-term survival of the loggerhead turtle (Gallagher et al., 1972; Worth and Smith, 1976).

One of the last major nesting rookeries in existence is on Hutchinson Island, Florida, where large resort motels, condominiums, restaurants and an electric generating facility are located. Although commercial I development is not uncoranon on the island, large tracts of uninhabited beach still remain. Research on the island has indicated that the areas of low development are the favored nesting areas for the adult turtles (see Section H, Nesting Turtles).

Loggerhead turtle hatchlings have an extremely short terres-

. trial existence. They emerge from the nest, primarily at night, and rapidly crawl across the beach and into the sea. They spend the rest of their lives in the sea except for the periodic nesting on the beach by the mature female. Because this post-hatching period is extremely sensitive, strong behavioral patterns for survival are ingrained in the hatchlings. These patterns restrict emergence from the nest to nocturnal periods and compel orientation and movement toward the sea.

Once in the sea, the turtles must be able to swim rapidly to an area

where food and protection are available.

Nest emergence of green turtles was examined by Hendrickson

(1958), who suggested that temperatures in excess of 33'C would

I-2 inhibit activity in the nest chamber and that hatchlings would resume activity only when lower temperatures returned at night. Nocturnal emergence is thought to enhance the survival of the sea turtle hatch-

lings by protecting the turtles from the high surface temperatures of tropical beaches and reducing predation by gulls and other visually oriented predators. Mrosovsky (1968) substantiated Hendrickson's ob-

servations but suggested 28.5'C as the level at which green turtles

become lethargic in the nest. Both authors agreed that thermal inhi-

bition of activity is a major factor limiting emergence of hatchling

sea turtles. Bustard (1967) suggested that the inactivity of a few turtles near the surface of the nest would have a dampening effect on the activity of those below, thereby limiting emergence of any turtles from the nest regardless of their nest position.

Once on the surface of the sand, the turtles move rapidly to

the sea. Ehrenfeld and Carr (1967) identified the sea-finding orien-

tation of hatchlings as primarily a visual process and suggested that the brighter portion of the environment, which under natural condi-

tions would be over the ocean, is the attractant for the hatchling turtles. Additional work on the mechanisms involved in the sea- finding ability of the turtles has been performed by Ehrenfeld (1968) Mrosovsky and Shettleworth (1968), and Mrosovsky (1970 and 1972).

These studies show that, for a variety of reasons, hatchling turtles

will move toward the brightest available light. It has been documented that artificial lights at developments near hatchi ng sites will disorient the turtles and they will migrate away from the sea (Philibosian, 1976). Mrosovsky (1968) examined green and hawksbill turtles for thermal inhibition of this phototropism but neglected to relate the conclusion that 29'C would cause cessation of activi ty by turtles to the fact that, once the turtles enter the water, natural ocean temperatures over much of the turtles'ange can be higher than 29'C.

MATERIALS AND METHODS

Hatchin and Maintenance

Loggerhead turtle nests were excavated from the sand on Hutch- inson Island, Florida, immediately after the adult female. left the nest site. Twenty-five or more eggs from each of 13 nests were transported by commercial aircraft to Atlanta, Georgia, where they were incubated in sand-filled 12-liter plastic pails until they hatched.

The incubation room temperature varied between 27'nd 30'C over the period of study. To reduce disturbance of the eggs, internal nest temperatures were not taken although they are known to be slightly higher than ambient temperature due to metabolic heat production by

the eggs (Carr and Hirth, 1961).

Nests were collected between 26 May and 5 August 1977, and

hatching occurred between 4 August and 22 October 1977. Turtles were allowed to emerge naturally from the nest to the surface of the sand.

No light was allowed in the room during incubation, hatching or the

I-4 holding period before testing to eliminate pre-test conditioning to a light stimulus. After the turtles emerged, the surface sand was wetted to prevent their dessication. No turtle was tested more than

48 hours after emergence to reduce the potential of different responses from turtles of different ages (Mrosovsky, 1968). Each turtle was used for one experiment only.

Test Tanks

Swimming tests were conducted in two shallow pools containing artificial seawater. The pools were each 8.2 x 0.5 m and were made with cement blocks lined with black plastic to retain the water.

For insulation, 2.5-cm thick styrofoam was placed between the plastic liner and the floor. Each tank was marked into four 1.8-m compart- ments with a 0.5-m turning area at each end (Figure I-l).

Temperature was controlled by regulating room temperature and by using iraoersion heaters controlled by one ot more high-precision mercury thermoregulators coupled to an electronic temperature control relay (Versatherm Models 2151 and 2149). Temperatures at the start of each test were controlled to +0.3'C. Heaters were removed from the tanks immediately before the swimming test to eliminate physical obstructions to swimming turtles. Heat loss from the water averaged less than 0.5'C during these tests. I

I I ~Lih R

Tests were conducted in a light-tight laboratory room enclosed in black plastic sheeting. The only illumination in the room was from two 15-watt lightbulbs reflecting on a white sheet at each end of the tank. These provided sufficient illumination for researchers to see the turtles swimming and constituted the only phototropic stimulus.

The light intensity for the phototropic stimulus was the lowest illumination that allowed the experimenters to observe the turtle. a Illumination in the tanks ranged from 7.2 lux at the distal end of the pool to 96.8 lux near the proximal end. Light levels at selected locations are given in Table I-1. Some light scattering and reflec- tion from the plastic sheeting were apparent, but the turtles oriented to the brightest light and swam toward it with little deviation.

Ex erimental Procedures

A swimming test consisted of placing a single turtle at one end of the tank and allowing him to swim toward the light at the far end of the tank. When the turtle completed the length of the tank, the light

stimulus was switched to the other end of the tank. The turtle would rapidly orient and swim toward the new light location. In this fashion,

turtles were tested for 30 or more lengths of the tank. The times required to swim each 1.8-m distance were measured with a digital stopwatch with cumulative interval timing. The swimming speeds for the four quarter- laps were averaged for all turtles. Data are presented in cm/sec.

= 1 lux 1 meter-candle. I-6 All turtles except those used for lethal temperature tests were returned to Hutchinson Island and released.

Thermal Re imes

To simulate natural thermal exposure, individual turtles were transferred directly from the sand in the nest pail,to the swimming tank without thermal acclimation. Test temperatures of 25.6, 27.8,

28.9, 30.0 and 33.3'C (Fahrenheit equivalents: 78, 82, 84, 86 and 92'F) were selected as reflective of summer ocean temperatures at Hutchinson

Island and elevated temperatures potentially encountered near the offshore discharge of the FPL facility. Since hatching turtles may encounter the thermal plume, additional tests were conducted in a fluctuating thermal regime to simulate the experience of a turtle swimming in and out of a.-thermal plume. After swimming speed had been established over 10 or 20

laps at one temperature', the turtles were quickly transferred to the second test tank containing water 2.3', 3.3'r 4.5'C warmer. The swimming speed at the increased temperatures was determined over the same number of laps I as the initial test, and the turtle was returned to the lower temperature to complete the last third of the test.

Lethal Effects 'emperatures in four 80-liter aquaria containing 60 liters of artificial seawater were thermostatically controlled within 0.1'C. Three groups of five turtles each were tested for thermal tolerance by raising the temperature 1'C per day from an ambient temperature of 28'C. Brett (1946) recommended this rate of thermal increase for fishes to I-7 ensure adequate acclimation time at each temperature increase. Data from Weathers and White (1971) and Spray and May (1972) indicate this

rate of thermal increase. is adequate for turtles. A fourth group was maintained at ambient temperature as a control. Attempts to establish

a sublethal criterion for the maximum thermal tolerance were unsuccessful,

so mortality criteria were used. Data from all tests were pooled and

percentage total mortality was plotted against time (Figure I-2) in the method of McLeese (1956). The temperature at which 50/ mortality is

predicted (LDsp) was determined to be 37.4'C for hatchling loggerhead turtles.

RESULTS

Naive turtles placed in the test pools exhibited a delayed orien-

tation to light that lasted less than a minute. The turtles remained

i n the first 0.5 m of the tank before slowly starting to swim toward the light. Swimming speeds i ncreased rapidly over the first five laps

as the turtles acclimated to their environment and exhibited a stronger response to the light stimulus. Most turtles had reached their maximum

I swimming speeds of 23 and 30 cm/sec between laps 7 and 10. The slow

acclimation period shown by all turtles in the first few laps probably

does not exist in the natural environment during the period when the hatchlings orient and crawl toward the sea.

A physiological capability and behavioral mechanism which allows

for a maximum effort as the turtle first encounters the water gives the

animal a selective advantage for getting through the dangerous surf zone.

Initial maximum effort was exhibited by turtles at all temperatures, with faster rates associated with the higher temperatures (Table I-2). I-8

Swimmin S eed at Constant Tem eratures After they had attained their maximum rates, turtles exposed to constant temperatures of 25.6'nd 27.8'C showed a gradual decrease in speed over the remaining laps of the test but stabilized at approximately 19.5 cm/sec. Turtles tested at 28.9'C showed a more marked decline in speed but also stabilized at approximately 19.5 cm/sec . Turtles tested at 30'C slowed considerably, and their speed had not stabilized by lap 60 ( Figure I-3) ~ Turtles tested at 33.3'C attained the highest maximum speed of almost 30 cm/sec at lap 7, then slowed an an erratic but precipitous fashion. The decline in speed was continuous over the remaining 35 laps that the turtles lasted.

Turtles tested at 30'C showed a greater reduction in speed than those tested at lower temperatures, but they continued to orient to the light and swim for the duration of the experiment. Of the seven turtles tested at 33.3'C, six stopped before completing the 60 laps.

These turtles remained at the surface of the water and swam aimlessly in the tank. They appeared active and alert but would not orient to

the light. A brighter light was substituted with no effect. When

non-responsi ve turtles were then placed in water at 30'C, they showed

no resumption of the phototropotaxis within five minutes. The single turtle that finished the test maintained an average rate of 15.5 cm/sec (individual turtles are not plotted in Figure I-2). I

l To test for significant differences between the swimming speed responses of turtles at di fferent temperatures (after they had reached their maximum rates), linear regression analysis was applied to the data from the time of maximum speed to the end of the test (Table I-3).

The results show significant differences between swimming speed reduction rates at all temperatures except 25.6 and 27.8'C, and 30.0 and 33.3'C (Table I-4).

In general, swimming speed and temperatures showed a positive relationship duri ng the initial 17 laps (122 meters) followed by an inverse relationship. However, the swimming speeds of turtles exposed to 28.9'C were higher than would be expected wi th this pattern ( Figure

I-3). Fry ( 1967) summari zed several studies and determined that organisms perform best when tested at the temperature to which they were acclimated. This concept could apply to the present study since the 28.9'C tests were conducted at the mean incubation temperature and all the turtles in this test were from the same nest. .The faster rates could also reflect nest variation that was ordinarily reduced by mixing nests and tests at other thermal regimes.

Swimmin S eeds in Fluctuatin Tem eratures Experiments to determine turtle responses to fluctuating thermal regimes were 'conducted with a base temperature, an elevated temperature and a return to base temperature, as specified in Table I-5. Tests using 25.6 and 30.0'C as the base temperatures were conducted over the course of both 30 and 60 laps. The swimming speeds of turtles subjected to. a fluctuating thermal regime were compared with the swimming speeds of turtles tested at a constant temperature that was equal to the base temperature. In the 30-lap tests, the turtles were exposed to each temperature for 10 laps. When the base temperature was 25.6'C, temperature elevations of both 3.3'nd 4.4'C produced an immediate increase in the swimming speed of the turtles.

During the 10 laps at this elevated temperature, the turtles showed a decline in swimming speed but maintained speeds above those of the

25.6'ase. At lap 21 the turtles were transferred back to the base temperature, and their swimming speeds showed a cold shock response by an immediate and pronounced decline in swimming speed. This shock response was reduced within one or two laps, and the swimmi ng speed returned to a constant but lower rate than the base speed (Figure I-4).

The same temperature regime (25.6/30.0/25.6') was used in a 60-lap test wi th thermal changes every 20 laps (Figure I-5). Although the thermal responses were not as pronounced as in the 30-lap tests, the turtles did show a general decrease in swimming speed during the higher temperature period and a sharp cold shock response when returned to water at 25.6'.

Only two turtles were tested at a 25.6/28.9/25.6'0-lap regime, and they showed extremely erratic responses. l Turtles exposed to thermal regimes of 30.0/32 ~ 2/30.0'nd

30.0/33.3/30.0'ver 30 laps showed a response pattern similar to that described for the 30-lap studies with the 25.6'ase (Figure I-6). Following the cold shock, turtles that had been exposed to 32.3'C recovered quickly to the rate of the control animals. Those that had been subjected to 33.3'C were comparatively slow to return

done to the control rate. Sixty-lap tests were only at 30.0/33.3/30.0'nd

are shown in Figure I-7. Turtles tested over the same thermal regimes showed similar patterns in both 30-lap and 60-lap tests.

DISCUSSION

Prange (1976) found the speed of juvenile green turtles forced to swim against a current ranged between 14 and 35 cm/sec. That result is consistent with the speeds observed in this study for loggerhead hatchlings, considering their smaller size and the different stimuli applied.

The responses of ectothermic animals to temperature have been widely investigated and reviewed by Precht et al. (1973). They concluded that, wi thin a moderate range of thermal tolerance, acti vi ty or speed in ectotherms generally increases with increases in temperature and then falls when a species-specific critical temperature level is exceeded. Although little work has been published on swimming speed in hatchling turtles, the activity reaction of the hatchlings to I 1 fluctuating environmental factors is typical of activity responses in other organisms. However, when hatchlings were transferred to a higher temperature, an immediate reduction in activity, which lasted for one lap, was observed. Since motivation to move toward light is extremely high, the immediate decreases observed in hatchling activity with increased temperature would be unexpected unless the organism were being exposed to stress conditions. The unexpected decrease in activity may reflect a reaction to handling stress rather than a thermal stress response (Saunders, 1963). However, several transfer tests without thermal change gave varied results which indicate that handling was not the primary influence.

The heat-induced lethargy in the nest described by Hendrickson

(1958) and Nrosovsky (1968) may influence the swimming speed of turtles in the'ater. Nrosovsky and Shettleworth (1968) examined the effects of temperature on crawling response in green turtle hatchli ngs. One- minute crawling tests after acclimation to temperatures of 19, 21, 23,

26 and 29'C showed reduced activity at higher temperatures. This supports the concept of reduced swimming speed at higher temperatures, although crawling tests over 26'C produced a marked 1ethargy while, in the present study, swimming activity limitation was not conspicious below 29-30'C. One-minute tests, however, are extremely short and may be influenced by a stress-associated reduction in activity due to handling. The differences in temperature level at which heat-limited responses are evident may also be due to the differences in thermal I

I history of the individual turtles, species, test duration or other factors. The thermal lethargy at 33'C reported by Hendrickson (1958) corroborates the present study. This lethargy in swimming turtles was primarily a cessation of the phototropotaxis rather than a loss of motility. It is not known at present whether this response is reversible.

Although additional data on physiological stress are needed, temperatures in the range tested should not be stressful because the mean ocean temperature at Hutchinson Island during the July, August, and September period of maximum emergence is about 30'C. The relatively high lethal temperature (LDsp) of 37.4'C also indicates that these thermal ranges are not stressful to physiological systems.

SUMMARY

An environmental condition available to turtles swimmi ng off-

shore from Hutchi nson Island is an encounter with a thermal discharge

from the St. Lucie Plant. This plant emits a thermal plume with a

maximum surface discharge sT of 5.5'F. Turtles swimming at ambient

temperatures and encountering this rapid, but small, thermal increase

would be expected to show alterations in their swimming speeds. Experimental studies indicated that the turtle behavioral and physiological responses reflect both the amount of thermal increase and the absolute temperature to which they are exposed. I

l The predicted temperature at which 50! mortality of hatchling turtles would occur was 37.4'C. This is considerably higher than surface temperatures associated with the offshore discharge at the St. Lucie Plant.

Temperatures of 33.3'C produced a reduction in swimming speed and an impairment of orientati on to brightness cues . Temperatures of

30'C, which are within normal maximum range for ambient ocean temperatures, are also high enough to produce a significantly reduced swimming speed in hatchling loggerheads. Temperatures below 30'C seem to have negligible effects on hatchling turtles. It should be noted that, while there is no evidence that potential offshore temperatures cause permanent impairment or mortality, additional work is needed to determine whether these temperatures influence the migration of hatchlings to the weed line .

LITERATURE CITED

Brett, J. R. 1946. Rate of gain of heat-tolerance in goldfish, carassius auratus. Publ. Ont. Fish. Res. Lab. 64:1-28.

Bustard, H. R. 1967. Mechanism of nocturnal emergence from the nest in green turtle hatchlings. Nature 214:317.

Carr, A., and H. Hirth. 1961. Social facilitation in green turtle siblings. Anim. Behav. 9:68-70.

Ehrenfeld, D. W. 1968. The role of vision in the sea-finding orientation of the green turtle (chelonia midas). 2. Orienta- tion mechanism and range o'f spectral sensitivity. Anim. Behav. 16:281-287. the sea Ehrenfeld, D. W ~ , and A. Carr. 1967. The role of vision in finding orientation of the green turtle (chelonia midas). Anim. Behav. 15:25-36.

Fletemeyer, J. R. 1978. The lost year. Sea Frontiers 24(l):23-26.

Fry, F. E . J. 1967. Responses of vertebrate poiki lotherms to temperature in A. H. Rose, ed. Thermobiology. Academic Press, New York. 653 pp.

Hendrickson, J. R. 1958. The green sea turtle, chelonia midas (Linn.) in Malaya and Sarawak. Proc. Zool. Soc. Lond. 130:455-535.

Gallagher, R. M., M. L. Hollinger, R. M. Ingle, and C. R. Futch. 1972. Marine turtle nesting on Hutchinson Island, Florida, in 1971. Fla. Dept. Nat. Resour., Mar. Res. Lab. Spec. Sci. Rept. No. 37. pp. 1-17.

McLeese, D. W. J. 1956. Effect of temperature, salinity and oxygen on survival of lobsters. J. fish Res. Bd. Canada. 13:247-272.

Mrosovsky, N. 1968. Nocturnal emergence of hatchling sea turtles: Con- trol by thermal inhibition of activity. Nature 220:1338-1339.

Mrosovsky, N. 1970. The influence of the sun's position and elevated cues on the orientation of hatchling sea turtles. Anim. Behav. 18:648-651.

Mrosovsky, N. 1972. The water finding ability of sea turtles. Brain, Behavior and Evolution 5:202-225.

Mrosovsky, N., and S. J. Shettleworth. 1968. Wavelength preferences and brightness cues in the water finding behaviour of sea turtles. Behaviour 32:211-257.

Philibosian, R. 1976. Disorientation of hawksbill turtle hatchlings, ErehnocheIys imbricata, by stadium lights. Copeia 1976(4);824.

Prange, H. D. 1976. Energetics of swimming of a sea turtle. J. Exp. Biol. 64:1-12.

Precht, H., J ~ Christophersen, H. Hensel, and W. Larcher. 1973. Temperature and life. Springer-Verlag, New York. 779 pp.

Saunders, R. L. 1963. Respiration in the Atlantic cod. J. Fish. Res. Bd. Canal. 30:373-386.

Spray, D. C., and M. L. May. 1972. Heating and cooling rates in four species of turtles. Comp. Biochem. Physiol. 41A:507-522.

Weathers, W. W., and F. N. White. 1971. Physiological thermor'egulation in turtles. Am. J. Physiol. 221:704-710.

Worth D. F., and J. B. Smith. 1976. Marine turtle nesting on Hutchinson Island, Florida, in 1973. Fla. Dept. Nat. Res., Mar. Res. Lab. Spec. Sci. Rept. No. 18. pp. 1-17. I

I Figure I-1. Diagrammatic view of hatchling loggerhead turtle testing tanks with one of four lights in operati'on. i E

M W W W Rl W W W W W M W W W %$ k% W W W 100

60 C) LD 50

37.4 C

33 34 35 36 37 38 39 TEMPERATURE ('C) Figure I-2. The relationship between percentage total mortality and temperature for hatchling loggerhead turtles. I

I 30~

---"-- ~ "...." ""~ / .... II 25 I

Ld I 15 fD

10 25 6'C 27.8 'C ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 28.9 30.0 C vr '3 3

Lap number 10 20 30 40 50 60 360 432 Distance (m) 72 144 216 288

Figure I-3. Swinming speed of hatchling loggerhead turtles at various temperatures (line fitted by inspection). I I I

I I 30~

EJ 2$ E

I 15 I I I fI I I I C 10: I 256-25.6-25.6 ~ e ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ + 25,6 28 9 25k C ———————25.6 -30.0 - 256 C

Lap number 10 20 30 Distance (m) . 72 144 216 Figure I-4. Average swimming speeds over 30 laps for hatchling loggerhead turtles exposed to three temperature regimes: one constant at 25.6'C, and two fluctuating every 10 laps with a base of 25.6'C. I I I

I l I 30~ 25.6-25.6-256 "C """~ ~ - ~ ~ ~ ~ ~ ~ . ~ ~ ~ ~ 256-28 9-256'r 25.6-30 0 256 C 25

V 2(h 6 lal I 15 I I

I z t

10: I

).ap number )0 20 30 40 50 60 360 Ols)ance (m) 72 )44 2)6 288 432

Figure I-5. Average swimming speed over 60 laps of hatchling loggerhead turtles exposed to three temperature regimes: one constant at 25.6'C, and two fluctuating every 20 laps with a base of 25 ''C. I I I

I I

I I I I W W W W W M W W M

—300-300-300 "C 30 """"'""""~ ~ '0.0-32.2-30.0"C 300-33.3-30.0 C

Ep 2$ E

I 15

Lap number 10 20 30 Distance (m) 72 144 21b Figure I-6. Average swimming speed over 30 laps of hatchling loggerhead turtles exposed to three temperature regimes: one constant at 30.0'C, and two fluctuating every 10 laps with a base of 30.0'C. I

I I

I I 30~

30.0-30.0-3Q P ". 3p.0-33.3-30.0 C

20'

10:

Lap number 10 20 30 4Q 50 60 Oistance (n) 72 144 216 288 360 432

Figure I-7. Average swimming speed over 60 laps of hatchling loggerhead turtles exposed 'o telo temperature regimes: one constant at 30.0'C and one fluctuating every 20 laps with a base of 30.0'C. TABLE I-l

LIGHT INTENSITY AT SELECTED DISTANCES ALONG EXPERIMENTAL TANKS HATCHLING TURTLE EXPERIMENTS 1977

a Distances in meters to end of tank Lux

8.2 7.2 7.7 7.7 5.9 10.7 4.1 20.0 2.3 42.9 0.5 96.8

= 1 lux 1 meter-candle. JI f r,

h I I

I TABLE I-2

AVERAGE SWIMMING SPEED IN CM/SEC AT 10-LAP INTERVALS FOR TURTLES TESTED AT SELECTED TEMPERATURES HATCHLING TURTLE EXP fRIMENTS 1977 emperature 'C 10 20 30 50 60

25.6 22.8 22.4 20.8 23.1 21.5 18.8

27.8 23. 5 22.1 20.4 18.8 19. 3 19.0

28.9 27.0 24.4 23.9 19 ~ 5 20.9 27.1'1.6. 30.0 25.4 16.4 12.8 14.2 12.6 33.3 28.3 20.2 17.3 10.5

I-26 I

I TABLE I-3

RESULTS OF REGRESSION ANALYSES OF SPEED AND DISTANCE (LAP) FROM MAXIMUM TURTLE SPEED TO END OF TEST HATCHLING TURTLE EXPERIMENTS 1977

rror sum of Tem erature 'C Slo e b Intercept a s uares N 25.6 -0.052 23.610 0.01421 270 27.8 -0.079 23.170 0.02919 200 28.9 -0.178 29.502 0.01845 190 30.0 -0.264 26.024 0.01486 450

33. 3 -0.308 28.125 0 .04031 169

I-27 I '

I TABLE I-4

RESULTS OF < TEST FOR SIGNIFICANT DIFFERENCES BETWEEN REGRESSION SLOPES HATCHLING 'TURTLE EXPERIMENTS 1977

Tem erature 33.3 30.0 28.9 27.8

25.6 9.37* 14.53* 7.81* 1. 26

27.8 6.59* 10.33* 4 00* 28.9 4.26* 5.43* 30.0 1.79 33.3

*Significant at 0.05.

I-28 1 TABLE I-5

THERNL REGIMES FOR FLUCTUATING TEMPERATURE TESTS HATCHLING TURTLE EXPERIMENTS 1977

Temperature regime 'C La s

25. 6 - 28. 9 - 25. 6 30

25.6 - 30.0 - 25.6 30

30.0 - 32.2 - 30.0 30

30.0 - 33.3 - 30.0 30

I-29